Combined fuel injection pump structure

Abstract

The utility model relates to a combined fuel injection pump structure which comprises a combined pump shell, a cam shaft and a plurality of single fuel injection pumps, an inner cavity is formed in the lower portion of the combined pump shell, a plurality of installation through holes are formed in the upper portion of the combined pump shell, and lower ports of the installation through holes are communicated with the inner cavity. The multiple single fuel injection pumps are inserted into the multiple installation through holes from top to bottom respectively, the cam shaft is installed in the inner cavity, the multiple single fuel injection pumps are controlled by the cam shaft, and the wall portion, located below the multiple installation through holes, of the combined pump shell is of an integrally-formed closed structure. The oil leakage risk of the combined oil injection pump structure can be reduced, and the disassembly and assembly convenience and the maintenance convenience of the combined oil injection pump structure can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of diesel engine electronically controlled fuel injection systems, in particular to a combined fuel injection pump structure. Background Art

[0002] In the prior art, the combined pump structure is usually composed of a plurality of electronically controlled unit fuel injection pumps assembled and installed. The combined pump structure usually includes a combined pump body, in which a plurality of mounting cavities for mounting the electronically controlled unit fuel injection pumps are arranged. The electronically controlled unit fuel injection pump usually includes a plunger pair, a plunger spring, a spring disk and a guide piston assembly installed in the mounting cavity. One end of the plunger spring is pressed on the spring disk installed in the mounting cavity, and the other end of the plunger spring is pressed on the spring seat connected to the guide piston assembly. The combined pump in the prior art has the following technical problems:

[0003] The plunger pair is installed into the installation cavity from the upper side of the combined pump body, and the plunger spring, spring plate and guide piston assembly are installed into the installation cavity from the lower side of the combined pump body, which has the problem of complicated disassembly and assembly;

[0004] Since the plunger spring, spring disk and guide piston assembly need to be installed into the installation cavity from the bottom side of the combined pump body, it is necessary to open a plurality of process holes at the bottom of the combined pump body. The process holes are used to provide installation channels for the plunger spring, spring disk and guide piston assembly. The provision of process holes greatly increases the risk of oil leakage in the combined pump body.

[0005] For example, the electrically controlled combined pump assembly proposed in the Chinese patent application with application number CN200420105472.5 adopts the above-mentioned combined pump structure, in which a process hole for providing a mounting channel is provided. Utility Model Content

[0006] The purpose of the utility model is to provide a combined fuel injection pump structure to alleviate or eliminate at least one of the above-mentioned technical problems.

[0007] The utility model describes a combined fuel injection pump structure, comprising a combined pump housing, a camshaft and a plurality of unit fuel injection pumps, wherein an inner cavity is arranged at the lower portion of the combined pump housing, a plurality of mounting through holes are arranged at the upper portion of the combined pump housing, a plurality of lower ports of the mounting through holes are communicated with the inner cavity, a plurality of the unit fuel injection pumps are respectively inserted into the plurality of mounting through holes from top to bottom, the camshaft is installed in the inner cavity, a plurality of the unit fuel injection pumps are controlled by the camshaft, and a wall portion of the combined pump housing located below the plurality of mounting through holes is an integrally formed closed structure.

[0008] Optionally, the plurality of unit fuel injection pumps each include a plunger assembly and a guide piston assembly which are separately arranged from each other, the guide piston assembly slidingly cooperates with the mounting through hole, the plunger assembly includes a plunger sleeve inserted in the mounting through hole, a plunger slidingly cooperates with the plunger hole of the plunger sleeve, a lower spring seat connected to the lower end of the plunger, and a plunger spring clamped between the lower spring seat and the plunger sleeve, and a stop structure for preventing the plunger from downwardly detaching from the plunger sleeve is provided between the plunger and the plunger sleeve.

[0009] Optionally, the plunger sleeve includes a plunger sleeve body that cooperates with the mounting through hole and a first reduced diameter section connected to the lower side of the plunger sleeve body, the outer diameter of the first reduced diameter section is smaller than the outer diameter of the plunger sleeve body, and the upper end of the plunger spring is supported on a step surface between the plunger sleeve body and the first reduced diameter section.

[0010] Optionally, the stop structure includes a support plate detachably fixedly connected to the lower end of the plunger sleeve and a support surface arranged on the plunger, and the support plate is used to block the support surface to prevent the plunger from detaching downward from the plunger sleeve.

[0011] Optionally, the plunger includes a plunger body and a second reduced diameter section connected to the lower side of the plunger body, the plunger body is slidingly matched with the plunger hole of the plunger sleeve, the outer diameter of the second reduced diameter section is smaller than the outer diameter of the plunger body, and the step surface between the second reduced diameter section and the plunger body is the support surface.

[0012] Optionally, the support plate surrounds the periphery of the second reduced diameter section, and the support plate is fixedly connected to the lower end surface of the plunger sleeve by screws.

[0013] Optionally, a terminal head is provided at the lower end of the plunger, and the lower spring seat is supported downward on the terminal head.

[0014] Optionally, the guide piston assembly includes a guide piston slidably engaged with the mounting through hole and a roller mounted on the lower portion of the guide piston, wherein the roller contacts a cam of the camshaft.

[0015] Optionally, the plunger assembly further includes a bypass valve component fixedly connected to the plunger sleeve.

[0016] Optionally, the mounting through hole is a straight circular hole.

[0017] The utility model helps to reduce the risk of oil leakage of the combined fuel injection pump structure, and helps to improve the convenience of disassembly and assembly and maintenance of the combined fuel injection pump structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a structural schematic diagram of the combined fuel injection pump structure described in some embodiments;

[0019] Figure 2 Schematic diagram of the structure of the unit fuel injection pump described in some embodiments.

[0020] Among them, 1-combination pump housing; 2-wall; 3-side hole; 4-mounting seat; 5-camshaft; 6-mounting through hole; 7-bypass valve component; 8-plunger sleeve body; 9-first reduced diameter section; 10-first step surface; 11-plunger body; 12-second reduced diameter section; 13-end; 14-support plate; 15-screw; 16-lower spring seat; 17-bayonet; 18-plunger spring; 19-guide piston assembly; 20-roller. DETAILED DESCRIPTION

[0021] The following will describe the implementation of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0022] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0023] like Figure 1 and Figure 2 A combined fuel injection pump structure shown includes a combined pump housing 1, a camshaft 5 and a plurality of unit fuel injection pumps. An inner cavity is provided at the lower portion of the combined pump housing 1, a plurality of mounting through holes 6 are provided at the upper portion of the combined pump housing 1, lower ports of the plurality of mounting through holes 6 are connected to the inner cavity, a plurality of unit fuel injection pumps are respectively inserted into the plurality of mounting through holes 6 from top to bottom, the camshaft 5 is installed in the inner cavity, the plurality of unit fuel injection pumps are controlled by the camshaft 5, and a wall portion 2 on the combined pump housing 1 located below the plurality of mounting through holes 6 is an integrally formed closed structure.

[0024] By adopting the above technical solution, the single fuel injection pump is inserted into the installation through hole 6 from top to bottom, and the wall portion 2 located below the multiple installation through holes 6 on the combined pump housing 1 is an integrally formed closed structure, avoiding the solution of setting a process hole at the bottom of the combined pump housing 1 in the prior art, and ensuring the structural integrity of the bottom of the combined pump housing 1. On the one hand, it can reduce the risk of oil leakage of the combined fuel injection pump structure and reduce the use of sealing rings and blocking covers; on the other hand, it makes the structure of the bottom of the combined pump housing 1 more complete, which helps to ensure the structural strength of the bottom of the combined pump housing 1.

[0025] In some embodiments, multiple single fuel injection pumps all include a plunger assembly and a guide piston assembly 19 that are separately arranged from each other. The guide piston assembly 19 is slidably matched with the installation through hole 6. The plunger assembly includes a plunger sleeve inserted in the installation through hole 6, a plunger slidably matched with the plunger hole of the plunger sleeve, a lower spring seat 16 connected to the lower end of the plunger, and a plunger spring 18 clamped between the lower spring seat 16 and the plunger sleeve. A stopper structure for preventing the plunger from disengaging from the plunger sleeve downward is provided between the plunger and the plunger sleeve. By adopting the above technical solution, the single fuel injection pump adopts a split structure, and the guide piston assembly 19 can be installed in the installation through hole 6 first. After the guide piston assembly 19 is installed in place, the plunger assembly is inserted into the installation through hole 6 from top to bottom.

[0026] The above-mentioned technical solution can meet the demand of installing the unit fuel injection pump from top to bottom, and there is no need to disassemble and replace the guide piston assembly 19 when replacing the wearing parts of the unit fuel injection pump. It has the characteristics of convenient disassembly and assembly, low maintenance cost and good maintainability. In the above-mentioned technical solution, the various components of the plunger assembly are connected together by reasonably setting the structure of the plunger assembly, which facilitates the insertion and disassembly of the plunger assembly. In the specific implementation, the plunger sleeve and the plunger constitute a plunger pair, and the setting of the plunger hole, plunger cavity, and oil channel inside the plunger sleeve can refer to the plunger pair in the prior art, such as an electronically controlled unit pump proposed in the patent application with application number CN202321400305.2, which will not be repeated here. In the specific implementation, the plunger sleeve can be an integrally formed part, and the plunger can be an integrally formed part.

[0027] In some embodiments, the plunger sleeve includes a plunger sleeve body 8 that matches the mounting through hole 6 and a first reduced diameter section 9 connected to the lower side of the plunger sleeve body 8. The outer diameter of the first reduced diameter section 9 is smaller than the outer diameter of the plunger sleeve body 8. A first step surface 10 facing downward is provided between the plunger sleeve body 8 and the first reduced diameter section 9. The upper end of the plunger spring 18 is supported on the first step surface 10. The plunger spring 18 is sleeved on the periphery of the first reduced diameter section 9 and the second reduced diameter section 12. By adopting the above technical solution, the plunger sleeve is set into a stepped structure with a larger upper portion and a smaller lower portion, so that the first step surface 10 can be formed, which provides convenience for arranging the plunger spring 18.

[0028] In some embodiments, the stop structure includes a support plate 14 detachably fixedly connected to the lower end of the plunger sleeve and a support surface provided on the plunger, and the support plate 14 is used to block the support surface to prevent the plunger from disengaging from the plunger sleeve downward. The above technical solution is adopted to form a stop structure using the support plate 14 and the support surface, which has the characteristic of being easy to implement. By providing a detachable stop structure, the plunger spring can be pressed between the support surface and the lower spring seat.

[0029] In some embodiments, the plunger includes a plunger body 11 and a second reduced diameter section 12 connected to the lower side of the plunger body 11, the plunger body 11 is slidably matched with the plunger hole of the plunger sleeve, the outer diameter of the second reduced diameter section 12 is smaller than the outer diameter of the plunger body 11, and there is a second step surface facing downward between the second reduced diameter section 12 and the plunger body 11, and the second step surface is the support surface. The above technical solution has the characteristics of being easy to implement.

[0030] In some embodiments, the support plate 14 surrounds the periphery of the second reduced diameter section 12, and the support plate 14 is fixedly connected to the lower end surface of the plunger sleeve by screws 15. In the above technical solution, the support plate 14 is fixedly installed by screws 15, which has the characteristics of stable structure and easy implementation.

[0031] In some embodiments, the lower end of the plunger is provided with a terminal 13, and the lower spring seat 16 is supported downward on the terminal 13. In the above technical solution, the lower spring seat 16 is used to support the plunger spring 18. In a specific implementation, the terminal 13 is connected to the lower side of the second reduced diameter section 12, and the outer diameter of the terminal 13 is larger than the outer diameter of the second reduced diameter section 12. A bayonet 17 is provided on one side of the lower spring seat 16, and the bayonet 17 is used to clamp on the second reduced diameter section 12, so that the edge of the bayonet 17 can be supported downward on the terminal 13. The bayonet 17 is provided on the lower spring seat 16, which has the characteristic of easy assembly.

[0032] As a preferred example, the plunger includes a plunger body 11, a second diameter-reducing section 12 and a terminal 13 connected in sequence, the outer diameter of the terminal 13 is larger than the outer diameter of the second diameter-reducing section 12, the outer diameter of the plunger body 11 is larger than the outer diameter of the second diameter-reducing section 12, the support plate 14 is annular, the inner diameter of the support plate 14 is not smaller than the outer diameter of the terminal 13, the inner diameter of the support plate 14 is larger than the outer diameter of the second diameter-reducing section 12, and the inner diameter of the support plate 14 is smaller than the outer diameter of the plunger body 11. The above technical solution has the characteristic of easy assembly.

[0033] In some embodiments, the guide piston assembly 19 includes a guide piston that slides with the mounting through hole 6 and a roller 20 installed at the lower part of the guide piston. The roller 20 contacts the cam of the camshaft 5 to form a cam mechanism. The rotation of the camshaft 5 can drive the guide piston assembly 19, the lower spring seat 16 and the plunger to reciprocate up and down, thereby driving the unit fuel injection pump to work.

[0034] In some embodiments, the plunger assembly further comprises a bypass valve component 7 fixedly connected to the plunger sleeve. In specific implementation, the valve member in the bypass valve component 7 can be driven by an electromagnetic component, which is controlled by an ECU and can realize the electronic control function of the unit fuel injection pump.

[0035] In some embodiments, the mounting through hole 6 is a straight circular hole, which facilitates the installation of the unit fuel injection pump from top to bottom.

[0036] In some embodiments, a side hole 3 for installing the camshaft 5 is provided at the lower part of the combined pump housing 1. The side hole 3 provides a channel for loading the camshaft 5 into the inner cavity. A mounting seat 4 for rotatably supporting the camshaft 5 can be installed at the side hole 3.

[0037] In specific implementation, a fuel inlet and an oil channel for delivering fuel to multiple single fuel injection pumps are provided in the combined pump housing 1. The rotation of the camshaft 5 of the combined fuel injection pump structure can drive the guide piston assembly 19, the lower spring seat 16 and the plunger of the single fuel injection pump to reciprocate up and down. The ECU is connected to the electromagnetic component corresponding to the bypass valve component 7. The ECU gives a current signal according to demand to control the valve switch in the bypass valve component 7, realizes the fuel pressure build-up and pressure relief in the plunger cavity of the plunger sleeve pair, and can control the opening and closing of the injector connected to the fuel outlet of the combined fuel injection pump structure or the single fuel injection pump through the pipeline, thereby controlling the injection timing and injection amount of the fuel injected into the cylinder.

[0038] The above embodiments are only preferred embodiments for fully illustrating the present utility model, and the protection scope of the present utility model is not limited thereto. Equivalent substitutions or changes made by technicians in the technical field on the basis of the present utility model are all within the protection scope of the present utility model. In the description of this specification, the description of reference terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics of the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0039] In the description of the present invention, it should be understood that the terms "upper", "lower" and the like indicate directions based on the attached Figure 1 The orientations represented by the coordinate system are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

Claims

1. A combined fuel injection pump structure, characterized in that: It includes a combination pump housing, a camshaft and multiple single fuel injection pumps, wherein an inner cavity is arranged at the lower portion of the combination pump housing, and multiple mounting through holes are arranged at the upper portion of the combination pump housing, and lower ports of multiple mounting through holes are communicated with the inner cavity, and multiple single fuel injection pumps are respectively inserted into the multiple mounting through holes from top to bottom, and the camshaft is installed in the inner cavity, and multiple single fuel injection pumps are controlled by the camshaft, and the wall portion of the combination pump housing located below the multiple mounting through holes is an integrally formed closed structure.

2. The combined fuel injection pump structure according to claim 1, characterized in that: The plurality of unit fuel injection pumps each include a plunger assembly and a guide piston assembly which are separately arranged from each other, the guide piston assembly slidingly cooperates with the mounting through hole, the plunger assembly includes a plunger sleeve inserted in the mounting through hole, a plunger slidingly cooperates with the plunger hole of the plunger sleeve, a lower spring seat connected to the lower end of the plunger, and a plunger spring clamped between the lower spring seat and the plunger sleeve, and a stop structure for preventing the plunger from downwardly detaching from the plunger sleeve is provided between the plunger and the plunger sleeve.

3. The combined fuel injection pump structure according to claim 2, characterized in that: The plunger sleeve includes a plunger sleeve body that cooperates with the mounting through hole and a first reduced diameter section connected to the lower side of the plunger sleeve body, the outer diameter of the first reduced diameter section is smaller than the outer diameter of the plunger sleeve body, and the upper end of the plunger spring is supported on a step surface between the plunger sleeve body and the first reduced diameter section.

4. The combined fuel injection pump structure according to claim 2, characterized in that: The stop structure comprises a support plate detachably fixedly connected to the lower end of the plunger sleeve and a support surface arranged on the plunger, and the support plate is used to block the support surface to prevent the plunger from falling off the plunger sleeve.

5. The combined fuel injection pump structure according to claim 4, characterized in that: The plunger includes a plunger body and a second reduced diameter section connected to the lower side of the plunger body. The plunger body is slidably matched with the plunger hole of the plunger sleeve. The outer diameter of the second reduced diameter section is smaller than the outer diameter of the plunger body. The step surface between the second reduced diameter section and the plunger body is the support surface.

6. The combined fuel injection pump structure according to claim 5, characterized in that: The support plate surrounds the periphery of the second reduced diameter section, and the support plate is fixedly connected to the lower end surface of the plunger sleeve by screws.

7. The combined fuel injection pump structure according to claim 2, characterized in that: The lower end of the plunger is provided with a terminal head, and the lower spring seat is supported downward on the terminal head.

8. The combined fuel injection pump structure according to claim 2, characterized in that: The guide piston assembly comprises a guide piston slidably matched with the mounting through hole and a roller mounted at the lower part of the guide piston, wherein the roller contacts the cam of the camshaft.

9. The combined fuel injection pump structure according to claim 2, characterized in that: The plunger assembly also includes a bypass valve component fixedly connected to the plunger sleeve.

10. The combined fuel injection pump structure according to claim 1, characterized in that: The mounting through hole is a straight circular hole.

Images