JPH04132453U - Fuel injection pump tappet device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a tappet device for a fuel injection pump that can increase the allowable surface pressure by increasing both the width and diameter of the tappet roller without changing the dimensions between the cylinders. . [Structure] In a tappet device for a fuel injection pump that has a body pet 3 that slides within a tappet hole 2 of a housing 1 and converts rotational movement of a camshaft 13 into vertical movement of a plunger 9, the body pet 3 is It is characterized by being formed into a rectangular tube shape.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a tappet device for a fuel injection pump, and is particularly designed to withstand high-pressure fuel injection. This invention relates to a tappet device for a fuel injection pump.

0002

[Conventional technology]

Generally, in fuel injection pumps, the rotational movement of the camshaft is transferred to the top of the plunger. Tappet devices for converting downward motion are known.

0003 This kind of device has a housing 30, as shown in FIG. Inside 30, cylindrical tappet holes 31 are formed in multiple rows. This type A cylindrical body pet 32 is housed in the pet hole 31 so as to be movable up and down. A tappet roller 35 is connected to the lower half of the body pet 32 via a roller pin 33. It is rotatably supported. Spring seat in the upper half of body pet 32 A plunger 39 is connected via 37, and a spring is connected around this plunger 39. ring 41 is attached. Also, the body pet 32 has a tappet guide 42. The tappet guide 42 is fixed to the guide formed in the hole wall of the tappet hole 31. It is fitted into the groove 31a. 43 is a camshaft, and 45 is a cam.

0004 By the way, in recent years, with the demand for high-pressure fuel injection in engines, tappet In such a device, the surface pressure between the tappet roller 35 and the cam 45 tends to increase. As this surface pressure increases, many problems such as wear and damage occur. In order to solve this problem, both the width and diameter of the tappet roller 35 should be made as large as possible. It is desirable to increase the allowable surface pressure.

[0005]

[Problem that the idea aims to solve]

However, in the conventional configuration, since the body pet 32 is cylindrical, As shown in FIG. 4, either the width W or the diameter D of the roller 35 should be made larger. Even if it is possible to increase both, it is not possible to increase the allowable surface pressure that much. The problem is that you can't listen. Suppose that both width W and diameter D are increased. When the allowable surface pressure is increased, the diameter of the body pet 32 becomes larger. , these are arranged in multiple rows as shown in the figure, so the so-called pitch L between the cylinders is large. There is a problem that the injection pump becomes larger in size.

[0006] Therefore, the purpose of the present invention is to solve the above-mentioned problems of the conventional technology and to Both the width and diameter of the tappet rollers can be increased without changing the dimensions between them. , to provide a tappet device for a fuel injection pump that can increase allowable surface pressure. There is a particular thing.

[0007]

[Means to solve the problem]

In order to achieve the above object, the present invention is designed to slide within the tappet hole of the housing. Has a body pet and converts the rotational movement of the camshaft into the vertical movement of the plunger. In the tappet device of a fuel injection pump, the body pet is formed into a rectangular tube shape. It is characterized by:

[0008]

[Effect]

According to the present invention, since the body pet has a rectangular cylindrical shape, compared to the conventional one, First of all, the tappet guide as a stopper for the tappet is no longer required, and this tappet There is no need for a guide groove to accommodate the guide. Therefore, compared to the conventional , the number of man-hours required for processing is reduced, making it possible to manufacture fuel injection pumps at low cost. can. Also, the four sides of the body pet are in contact with the four hole walls of the tappet hole, respectively. Therefore, the entire surface is evenly touched, which is advantageous against wear. Furthermore, the so-called mind After making the pitch between the cylinders the same as the conventional pitch, we changed the width and diameter of the tappet roller. The allowable surface pressure can be increased without increasing the size of the fuel injection pump. can be increased, and there are fewer problems such as wear and damage even when the pressure is increased. It can sufficiently withstand the demands of high-pressure fuel injection of the engine.

[0009]

【Example】

An embodiment of the tappet device of the fuel injection pump according to the present invention is shown below in FIGS. 1 and 2. Explain with reference to.

0010 In FIG. 1, 1 indicates a housing of a fuel injection pump. This housing Tappet holes 2 are formed in multiple rows inside the tappet 1. A body pet 3 is housed so as to be vertically movable. The lower half of this body pet 3 A tappet roller 5 is rotatably supported through a roller pin 4 at the portion. Bo A plunger 9 is connected to the upper half of the data pet 3 via a spring seat 7. A tappet spring 11 is mounted around the plunger 9. 1 3 is a camshaft, and 15 is a cam.

[0011] According to this embodiment, the tappet hole 2 of the housing 1 has a cross section approximately The body pet 3 is formed into a rectangular shape and is housed therein so as to be able to move vertically. , as shown in FIG. 2, is formed into a rectangular tube shape. This square tubular body pet 3 A substantially rectangular roller hole 17 is formed in the roller hole 17, leaving a necessary wall thickness t. The tappet roller 5 is attached to the hole 17 as described above.

0012 Next, the operation of this embodiment will be explained.

[0013] When the camshaft 13 rotates, the cam 15 rotates integrally, changing the shape of the cam surface. Depending on the situation, the body tappet 3 moves up and down in the tappet hole 2, and at the same time, the body tappet 3 moves up and down in the tappet hole 2. The connector 9 moves up and down.

[0014] According to this embodiment, the tappet hole 2 of the housing 1 has a rectangular cross section. The body pet 3, which is housed therein so as to be able to move up and down, has a rectangular cylindrical shape. First of all, the tappet guide as a stopper for the tappet is no longer needed. At the same time, a guide groove for accommodating this tappet guide becomes unnecessary.

[0015] Therefore, the number of man-hours required for processing is reduced compared to conventional ones, so fuel injection The pump can be manufactured at low cost. Also, the 4 sides of Body Pet 3 are The tappet holes 2 and 4 contact the walls of the tappet hole 2, so they contact the entire surface evenly and prevent wear. It will be advantageous.

[0016] Furthermore, according to this embodiment, with reference to FIG. 2, the so-called pitch L between the cylinders is , the width W and diameter D of the tappet roller 5 are increased while keeping the same as the conventional pitch L. can do. Therefore, the allowable surface pressure can be increased without increasing the size of the fuel injection pump. It can be made larger, has less problems such as wear and damage even under high pressure, and is easy to use. It can sufficiently withstand the demands of high-pressure fuel injection in engines.

[0017] Although the present invention has been described above based on one embodiment, the present invention is limited to this. It is clear that this is not the case. For example, body data pet 3 is made of a rectangular tube. It is not necessary to make the outer shape of the part that accommodates the tappet roller 5 square. It is obvious that it can be made into a cylindrical shape.

[0018]

[Effect of the idea]

As is clear from the above explanation, according to the present invention, the body pet has a rectangular tube shape. First of all, compared to conventional ones, there is a tappet guide that acts as a stopper for the tappet. This eliminates the need for a guide groove to accommodate this tappet guide. Ru. Therefore, the number of man-hours required for machining is reduced compared to conventional ones, so fuel injection The injection pump can be manufactured at low cost. In addition, the so-called pitch between cylinders is The width and diameter of the tappet roller can be increased while maintaining the same pitch as before. Therefore, the allowable surface pressure can be increased without increasing the size of the fuel injection pump. Even when the pressure is increased, there are fewer problems such as wear and damage, and the fuel pressure of the engine is high. It can be made to be able to sufficiently withstand the demands of jetting.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a tappet device according to the present invention.

FIG. 2 is a cross-sectional view showing the body pet.

FIG. 3 is a longitudinal sectional view showing a conventional tappet device.

FIG. 4 is a cross-sectional view showing the body pet.

[Explanation of symbols]

1 Housing 2 Tappet hole 3 Body pet 5 Tappet roller 9 Plunger 13 Camshaft 15 cam

Claims (1)

[Scope of utility model registration request] 1. A tappet device for a fuel injection pump that has a body pet that slides within a tappet hole of a housing and converts rotational movement of a camshaft into vertical movement of a plunger, wherein the body pet has a rectangular cylindrical shape. A tappet device for a fuel injection pump, characterized in that it is formed as follows.