Title of Invention	TEST INJECTOR FOR CALIBRATION OF FUEL INJECTION PUMPS WITH HOLE-TYPE NOZZLE IN LIEU OF PINTLE TYPE NOZZLE
Abstract	The invention in general relates to calibration nozzle of a test fuel injector for fuel injection pumps. The present invention to provide a hole type nozzle in test injector which gives an improved fuel injection nozzle assembly for calibration of fuel injection pumps in test benches and the hole type nozzle have a better service life with stable delivery over its life time by controlled hydro grinding of nozzle spray hole. The present invention is simple to manufacture and less expensive.

Title of Invention

TEST INJECTOR FOR CALIBRATION OF FUEL INJECTION PUMPS WITH HOLE-TYPE NOZZLE IN LIEU OF PINTLE TYPE NOZZLE

Abstract

The invention in general relates to calibration nozzle of a test fuel injector for fuel injection pumps. The present invention to provide a hole type nozzle in test injector which gives an improved fuel injection nozzle assembly for calibration of fuel injection pumps in test benches and the hole type nozzle have a better service life with stable delivery over its life time by controlled hydro grinding of nozzle spray hole. The present invention is simple to manufacture and less expensive.

Full Text	FIELD OF INVENTION: The invention relates to a test injector with a hole type nozzle for calibrating the fuel injection pumps. PRIOR ART: Presently, various test benches are used for calibration of fuel Injection pump (eg. PE, VE & PF) during manufacture and service. These test benches use test injector to deliver a predetermined quantity of fuel/test oil. With this predetermined fuel/test oil delivery, the pump flow quantity will be calibrated. For example at set rotational speed of pump the quantity of fuel delivered should be 'x' mm3 using a test injector. Test accuracy is vital for the oil feed performance of injection pumps and basically associated directly with the operating power and the economy of the diesel engines. Test injector comprises of Nozzle holder and nozzle. Nozzle is the component which determines and controls the flow from injector. In conventional test injectors, either pintle type nozzle (fig. lA) or an orifice plate with nozzle(fig. lB) is used for controlled delivery of fuel or test oil. The figure 1A shows a design of test injector with nozzle holder and nozzle assembly. The nozzle is pintle type used for calibration purposes. The Figure 1B shows another design of test injector with an orifice plate and nozzle for calibration purposes. Nozzle: Used in fuel injection equipment to determine and control the quantity of fuel or test oil delivered. In any type of nozzle, the quantity of flow is controlled by partially/fully opening a hole using fuel pressure. Any nozzle has a nozzle body and needle sitting on the nozzle body (fig.lA). Because of low viscosity a minuscule needle movement is sufficient to release the amount of fuel or test oil. Pintle type nozzle : A type of nozzle, which has a pintle hole on nozzle body and a needle sitting on the tapered surface covering this hole (fig.lA). When used in an injector, the fuel pressure will cause the needle to lift thus allowing the fuel to flow through the hole (fig. 1A) Orifice plate: A flat disc or a plate with tiny holes drilled to tighter tolerance to allow the controlled quantity of fuel. In fuel injection pump calibration, it is often used with a nozzle to have tighter flow control tolerances over time. Hole type nozzle: Another type of nozzle which has a spay hole on nozzle body and a needle sitting on the tapered surface covering this hole but in a different manner (fig.2). The practice of pintle type nozzle (Figure 1A) for calibration of fuel injection pump in the existing art has limited life. It is difficult to manufacture the pintle nozzle with closer flow tolerances as desired for calibration. These nozzles are presently selected from a batch of manufactured nozzles. Hence, the cost of manufacturing is high. Further in the existing design of test injector with nozzle in figure 1B there are two items 1. orifice plate and 2. nozzle. Both these parts are manufactured for a very close tolerance. Hence, these are very expensive. OBJECT OF THE INVENTION:- A principal object of the present invention is to provide a hole type nozzle in test injector which gives an improved fuel injection nozzle assembly for calibration of fuel injection pumps in test benches. It is another object of the present invention to provide a hole type fuel injector with a single nozzle spray hole which is economically simple in design and can be manufactured at a relatively low cost. It is further object of the present invention to provide a hole type nozzle in test injector to achieve close tolerances for flow values easily for calibration and also a better service life with stable delivery over its life time. It is further object of the present invention to provide a hole type fuel injector which improves the calibration process of fuel injection pumps to achieve better engine emissions. BRIEF DESCRIPTION OF THE DRAWINGS Now the preferred embodiment of the present invention is illustrated in the accompanying drawings which are as follows: Figure 1A illustrates an existing art of test injector for calibrating a fuel injection pump with a pintle type nozzle. Figure 1B illustrates another existing art of test injector with nozzle and an orifice. Figure. 2 is a sectional elevation view of a single hole type nozzle used in test injector constructed In accordance with a preferred embodiment of the present invention; Figure 3 is an enlarged fragmentary sectional view of the nozzle of Fig. 2, illustrating the needle valve seat, and a sac hole formed in the lower part of the nozzle tip with a single axial spray hole. DESCRIPTION OF THE INVENTION: Fuel injection pumps need to be calibrated for its flow quantity. Fuel injection test bench is used for checking, adjusting and testing of fuel injection pump under normal operating conditions. The test injector is a means to calibrate the fuel Injection pumps. They are intended to simulate the function of a nozzle and nozzle holder assemblies in fuel injection system of diesel engine. The fuel/test oil is discharged from the nozzle connected to the fuel injection pump in a test bench. This discharge quantity is used as calibrating quantity for the pump. These nozzles have a close tolerance for flow values. Nozzles are so designed to efficiently determine fluid rate through a pipe. Standard test injectors are used in injection pump test-beds and are used routinely for testing and adjusting diesel engine injection pumps. ISO 14681:1998 calibration Fuelling pump testing- calibrating fuel injectors. This international standard specifies two types of calibrating injectors intended for testing and setting diesel fuel injection pumps on test benches. ISO. 7440-1 ISO-4010, ISO 7440-1:1991(E)- Road Vehicle - Fuel injection equipment testing calibration nozzle and holder assemblies. ISO 7878-2: 1991 - Fuel injection equipment - vocabulary - Part 2: Fuel injectors, ISO 7440-2: 1991 - Road vehicles - Fuel injection equipment testing - Part 2: Orifice plate flow measurement. ISO 4010 - Diesel Engines - Calibrating nozzle, delay pintle type, ISO 4008-3 - Fuel injection pump testing - Application and test procedures. Testing and calibration is done so that optimum fuel consumption/power output ratios are achieved. Figure 2 as per the invention can replace the existing art of figure 1A and figure IB. According to the present invention, the pintle nozzle in Figure 1A, orifice plate and nozzle in figure IB are replaced by a single hole- hole type nozzle. It is simpler to manufacture single hole-hole type nozzle compared to pintle nozzle or orifice plate and nozzle. Tighter flow tolerance of single hole-hole type nozzle is achieved by drilling or by electro-discharge machining of single hole followed by controlled hydro-grinding. Usage of single hole-hole type nozzle for calibration injector is a novel and inventive. According to the present invention, a calibrating nozzle of a test fuel injector for fuel injection pumps shall comprise a longitudinal nozzle body formed with a bore, a needle valve movably disposed in the bore, a valve seat formed at one end of the bore, a nozzle holder secured at the other end portion of the bore remote from the valve seat for supporting the valve member to move towards and away from the valve seat. A nozzle spring is positioned to normally urge the needle valve against the valve seat and a movable seat spring Is positioned to urge the needle valve away from the valve seat under pressure. Further a nozzle tip is formed in the nozzle body below the needle valve which enclosing the lower end of the valve bore. The nozzle tip of the nozzle body shall define a pressure chamber which is in fluid communication with the bore and further the nozzle tip is provided with a spray hole which formed on the valve bore below the valve seat. The nozzle tip formed as per the invention shall be characterized to form a sac type pressure chamber in the tip. Further the spray velocity is generated at the seat directly with the valve seat spring. The advantages of the invention are as follows: The present invention is unique and does not exist for calibration purposes. The present invention will perform the function of both orifice plate and the nozzle. The hole type nozzle will have a better service life with stable delivery over its life time. This is possible due to controlled hydro grinding of nozzle spray hole. The present invention is simple to manufacture and less expensive compared to existing prior arts. Usage of such hole type nozzles improves the quality of calibration of pumps, Better calibration results in better engine emissions. The present invention can be applied with many applications such as follows: All spray hole sizes- Diameter and length. Pressure stages (needle guide diameter X needle seat diameter). Sac hole forms Different types of hole type nozzle designs. WE CLAIMS 1. A calibrating nozzle of a test fuel injector for fuel injection pumps, the calibrating nozzle comprising - a longitudinal nozzle body; - a bore formed in the nozzle body; - a needle valve movably disposed in the bore; - a valve seat formed at one end of the bore; - a nozzle holder secured at the other end portion of the bore remote from the valve seat for supporting the valve member to move towards and away from the valve seat; - a nozzle spring positioned to normally urge the needle valve against the valve seat; - a movable seat spring positioned to urge the needle valve away from the valve seat under pressure; - a nozzle tip formed in the nozzle body below the needle valve and enclosing the lower end of the valve bore, the said tip defining therein a pressure chamber in fluid communication with the bore; and - a spray hole formed on the valve bore below the valve seat, - characterized in the tip defining a sac type pressure chamber characterized in the spray velocity generated at the seat directly with the valve seat spring.

Full Text

FIELD OF INVENTION:

The invention relates to a test injector with a hole type nozzle for calibrating the fuel injection pumps.

PRIOR ART:

Presently, various test benches are used for calibration of fuel Injection pump (eg. PE, VE & PF) during manufacture and service. These test benches use test injector to deliver a predetermined quantity of fuel/test oil. With this predetermined fuel/test oil delivery, the pump flow quantity will be calibrated. For example at set rotational speed of pump the quantity of fuel delivered should be 'x' mm3 using a test injector. Test accuracy is vital for the oil feed performance of injection pumps and basically associated directly with the operating power and the economy of the diesel engines.

Test injector comprises of Nozzle holder and nozzle. Nozzle is the component which determines and controls the flow from injector. In conventional test injectors, either pintle type nozzle (fig. lA) or an orifice plate with nozzle(fig. lB) is used for controlled delivery of fuel or test oil.

The figure 1A shows a design of test injector with nozzle holder and nozzle assembly. The nozzle is pintle type used for calibration purposes.

The Figure 1B shows another design of test injector with an orifice plate and nozzle for calibration purposes.

Nozzle: Used in fuel injection equipment to determine and control the quantity of fuel or test oil delivered. In any type of nozzle, the quantity of flow is controlled by partially/fully opening a hole using fuel pressure. Any nozzle has a nozzle body and needle sitting on the nozzle body (fig.lA). Because of low viscosity a minuscule needle movement is sufficient to release the amount of fuel or test oil.

Pintle type nozzle : A type of nozzle, which has a pintle hole on nozzle body and a needle sitting on the tapered surface covering this hole (fig.lA). When used in an injector, the fuel pressure will cause the needle to lift thus allowing the fuel to flow through the hole (fig. 1A)

Orifice plate: A flat disc or a plate with tiny holes drilled to tighter tolerance to allow the controlled quantity of fuel. In fuel injection pump calibration, it is often used with a nozzle to have tighter flow control tolerances over time.

Hole type nozzle: Another type of nozzle which has a spay hole on nozzle body and a needle sitting on the tapered surface covering this hole but in a different manner (fig.2). The practice of pintle type nozzle (Figure 1A) for calibration of fuel injection pump in the existing art has limited life. It is difficult to manufacture the pintle nozzle with closer flow tolerances as desired for calibration. These nozzles are presently selected from a batch of manufactured nozzles. Hence, the cost of manufacturing is high.

Further in the existing design of test injector with nozzle in figure 1B there are two items 1. orifice plate and 2. nozzle. Both these parts are manufactured for a very close tolerance. Hence, these are very expensive.

OBJECT OF THE INVENTION:-

A principal object of the present invention is to provide a hole type nozzle in test injector which gives an improved fuel injection nozzle assembly for calibration of fuel injection pumps in test benches.

It is another object of the present invention to provide a hole type fuel injector with a single nozzle spray hole which is economically simple in design and can be manufactured at a relatively low cost.

It is further object of the present invention to provide a hole type nozzle in test injector to achieve close tolerances for flow values easily for calibration and also a better service life with stable delivery over its life time.

It is further object of the present invention to provide a hole type fuel injector which improves the calibration process of fuel injection pumps to achieve better engine emissions.

BRIEF DESCRIPTION OF THE DRAWINGS

Now the preferred embodiment of the present invention is illustrated in the accompanying drawings which are as follows:

Figure 1A illustrates an existing art of test injector for calibrating a fuel injection pump with a pintle type nozzle. Figure 1B illustrates another existing art of test injector with nozzle and an orifice.

Figure. 2 is a sectional elevation view of a single hole type nozzle used in test injector constructed In accordance with a preferred embodiment of the present invention;

Figure 3 is an enlarged fragmentary sectional view of the nozzle of Fig. 2, illustrating the needle valve seat, and a sac hole formed in the lower part of the nozzle tip with a single axial spray hole.

DESCRIPTION OF THE INVENTION:

Fuel injection pumps need to be calibrated for its flow quantity. Fuel injection test bench is used for checking, adjusting and testing of fuel injection pump under normal operating conditions. The test injector is a means to calibrate the fuel Injection pumps. They are intended to simulate the function of a nozzle and nozzle holder assemblies in fuel injection system of diesel engine. The fuel/test oil is discharged from the nozzle connected to the fuel injection pump in a test bench. This discharge quantity is used as calibrating quantity for the pump. These nozzles have a close tolerance for flow values.

Nozzles are so designed to efficiently determine fluid rate through a pipe. Standard test injectors are used in injection pump test-beds and are used routinely for testing and adjusting diesel engine injection pumps.

ISO 14681:1998 calibration

Fuelling pump testing- calibrating fuel injectors.

This international standard specifies two types of calibrating injectors intended for testing and setting diesel fuel injection pumps on test benches.

ISO. 7440-1

ISO-4010,

ISO 7440-1:1991(E)- Road Vehicle - Fuel injection equipment testing calibration nozzle and holder assemblies.

ISO 7878-2: 1991 - Fuel injection equipment - vocabulary - Part 2: Fuel injectors,

ISO 7440-2: 1991 - Road vehicles - Fuel injection equipment testing - Part 2:

Orifice plate flow measurement.

ISO 4010 - Diesel Engines - Calibrating nozzle, delay pintle type,
ISO 4008-3 - Fuel injection pump testing - Application and test procedures.

Testing and calibration is done so that optimum fuel consumption/power output ratios are achieved.

Figure 2 as per the invention can replace the existing art of figure 1A and figure IB. According to the present invention, the pintle nozzle in Figure 1A, orifice plate and nozzle in figure IB are replaced by a single hole- hole type nozzle.

It is simpler to manufacture single hole-hole type nozzle compared to pintle nozzle or orifice plate and nozzle.

Tighter flow tolerance of single hole-hole type nozzle is achieved by drilling or by electro-discharge machining of single hole followed by controlled hydro-grinding. Usage of single hole-hole type nozzle for calibration injector is a novel and inventive.
According to the present invention, a calibrating nozzle of a test fuel injector for fuel injection pumps shall comprise a longitudinal nozzle body formed with a bore, a needle valve movably disposed in the bore, a valve seat formed at one end of the bore, a nozzle holder secured at the other end portion of the bore remote from the valve seat for supporting the valve member to move towards and away from the valve seat. A nozzle spring is positioned to normally urge the needle valve against the valve seat and a movable seat spring Is positioned to urge the needle valve away from the valve seat under pressure. Further a nozzle tip is formed in the nozzle body below the needle valve which enclosing the lower end of the valve bore. The nozzle tip of the nozzle body shall define a pressure chamber which is in fluid communication with the bore and further the nozzle tip is provided with a spray hole which formed on the valve bore below the valve seat.

The nozzle tip formed as per the invention shall be characterized to form a sac type pressure chamber in the tip. Further the spray velocity is generated at the seat directly with the valve seat spring.

The advantages of the invention are as follows:

The present invention is unique and does not exist for calibration purposes.

The present invention will perform the function of both orifice plate and the nozzle.

The hole type nozzle will have a better service life with stable delivery over its life time. This is possible due to controlled hydro grinding of nozzle spray hole.

The present invention is simple to manufacture and less expensive compared to existing prior arts.

Usage of such hole type nozzles improves the quality of calibration of pumps, Better calibration results in better engine emissions.

The present invention can be applied with many applications such as follows:

All spray hole sizes- Diameter and length.

Pressure stages (needle guide diameter X needle seat diameter).

Sac hole forms

Different types of hole type nozzle designs.

WE CLAIMS

1. A calibrating nozzle of a test fuel injector for fuel injection pumps, the calibrating nozzle comprising

- a longitudinal nozzle body;

- a bore formed in the nozzle body;

- a needle valve movably disposed in the bore;

- a valve seat formed at one end of the bore;

- a nozzle holder secured at the other end portion of the bore remote from the valve seat for supporting the valve member to move towards and away from the valve seat;

- a nozzle spring positioned to normally urge the needle valve against the valve seat;

- a movable seat spring positioned to urge the needle valve away from the valve seat under pressure;

- a nozzle tip formed in the nozzle body below the needle valve and enclosing the lower end of the valve bore, the said tip defining therein a pressure chamber in fluid communication with the bore; and

- a spray hole formed on the valve bore below the valve seat,

- characterized in the tip defining a sac type pressure chamber characterized in the spray velocity generated at the seat directly with the valve seat spring.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=OigzgHAK/MW7CdAj60e7tg==&loc=egcICQiyoj82NGgGrC5ChA==

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Patent Number

269562

Indian Patent Application Number

554/CHE/2008

PG Journal Number

44/2015

Publication Date

30-Oct-2015

Grant Date

28-Oct-2015

Date of Filing

05-Mar-2008

Name of Patentee

Robert Bosch GmbH

Applicant Address

STUTTGART, FEUERBACH,GERMANY

Inventors:

#	Inventor's Name	Inventor's Address
1	MR. MARUTHI	BOSCH LIMITED HOSUR ROAD, ADUGODI BANGALORE 560 030
2	MR. SUNDARRAMAN PICHAI	BOSCH LIMITED HOSUR ROAD, ADUGODI BANGALORE 560 030

PCT International Classification Number

N/A

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA