JPH094542A - Fuel feeding device - Google Patents

Abstract

PURPOSE: To provide a fuel feeding device simple in structure, excellent in durability, easy of manufacture, and inexpensive. CONSTITUTION: Where the diameter of a flat surface 41a of a tappet 41 is 2D, the width of a cam surface in the axial direction of a cam shaft is 2B, the sliding distance in the sliding direction of the flat surface 41a with the cam surface is 2L, the eccentricity in the width direction of the cam surface between the center axis 202 of the cam orthogonal to the axis of rotation of the cam and parallel to the center axis 201 of the flat surface 41a and the center axis 201 is e1 , and the eccentricity in the sliding direction between the center axis 202 of the cam and the center axis 201 of the flat surface 41a is e2 , then the inequalities (B-e1 )>D>(L+e2 ) are satisfied between the parameters. The flat surface 41a is constantly brought into line contact with the cam surface to prevent the peripheral edge part of the cam from being brought into contact with the flat surface 41a, and generation of eccentric wear or excessive stress concentration is prevented at the sliding part of the tappet 41 with the cam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system used in an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as a fuel supply device for an internal combustion engine, a rotary motion of a cam is converted into a reciprocal motion of a tappet, and a piston (plunger) that reciprocates together with the tappet pressure-feeds fuel. Those disclosed in Japanese Patent Publication No. 62-15486 and Japanese Utility Model Publication No. 62-15486 are known.

In the oil pump disclosed in Japanese Patent Laid-Open No. 48-9044, the flat surface of the outer wall of the bottom of the tappet and the cam surface are in direct sliding contact with each other. In addition, the actual public Sho 62-1548
In the fuel supply device disclosed in Japanese Unexamined Patent Publication No. 6, a tappet roller is provided on the tappet, and the rotational movement of the cam rotating with the cam shaft is converted into the reciprocating movement of the tappet roller and the piston.

[0004]

However, in the one disclosed in Japanese Patent Laid-Open No. 48-9044, since the flat surface of the tappet and the cam surface slide directly on each other, the tappet or the shape of the cam may cause a tappet. And uneven wear or excessive stress concentration occurs in the sliding part of the cam. In order to avoid uneven wear or excessive stress concentration of these sliding parts, if the requirements for the surface roughness and shape accuracy of the flat surface and the cam surface of the tappet become strict, there is a problem that the cost increases as a result.

Further, in the one disclosed in Japanese Utility Model Publication No. 62-15486, the sliding resistance between the tappet and the cam can be alleviated by attaching the tappet roller to the tappet, but the number of parts is increased. There is a problem that the number of assembling steps increases and the size of the apparatus increases, which further increases the manufacturing cost. The present invention has been made to solve such a problem, and an object of the present invention is to provide a fuel supply device that has a simple structure, excellent durability, is easy to manufacture, and is inexpensive.

[0006]

In order to achieve the above object, a fuel supply device according to claim 1 of the present invention has a tappet having a flat surface on a bottom outer wall, and a cam surface which slides on the flat surface. A fuel supply device that includes a cam that reciprocally drives the tappet as the camshaft rotates and a plunger that reciprocates together with the tappet, and that pressurizes and pumps the fuel sucked into the pressurizing chamber as the plunger reciprocates. And the flat surface diameter is 2D, the cam surface width in the axial direction of the camshaft is 2B, the sliding distance in the sliding direction between the flat surface and the cam surface is 2L, and it is orthogonal to the rotation axis of the cam. Then, the eccentric amount in the width direction of the cam surface between the central axis of the cam parallel to the central axis of the flat surface and the central axis of the flat surface is e ₁ , the central axis of the cam and the central axis of the flat surface are Sliding direction When a definitive eccentricity and e _2, and satisfies the _{(B-e 1)> D} > (L + e 2).

The fuel supply system according to claim 2 of the present invention is
The fuel supply device according to claim 1, wherein a tapered surface is formed on the outer periphery of the flat surface in a direction away from the cam as it extends radially outward. The fuel supply device according to claim 3 of the present invention is the fuel supply device according to claim 2, wherein the tappet is formed in a bottomed cylindrical shape, and an oil drain hole communicating between the inside and outside of the tappet is formed at the tapered surface position. It is characterized by doing.

[0008]

According to the fuel supply apparatus of the first or second aspect of the present invention, the flat surface of the outer wall of the tappet bottom portion and the cam surface slide directly. Furthermore, the flat surface diameter of the tappet is 2D, and the cam surface width in the axial direction of the camshaft is 2D.
B, the sliding distance in the sliding direction between the flat surface and the cam surface is 2
L, the eccentricity in the width direction of the cam surface between the center axis of the cam and the center axis of the flat surface that is orthogonal to the rotation axis of the cam and parallel to the center axis of the flat surface, e ₁ , the center axis of the cam and the center of the flat surface When the eccentricity in the sliding direction with the shaft is e ₂ , by forming the tappet so that (B−e ₁ )>D> (L + e ₂ ), the flat surface of the tappet and the cam surface are always linear. By contacting and the outer peripheral edge of the cam not sliding on the flat surface of the tappet, it is possible to reduce sliding wear of the tappet and the cam and to avoid excessive stress concentration without increasing the number of parts. Therefore, the durability can be improved without hardening the tappet or the cam, and the tappet and the cam can be easily manufactured.

According to the third aspect of the fuel supply apparatus of the present invention, the tappet and the cam are slid by forming the oil drain hole, which is formed in a cylindrical shape with a bottom and which communicates the inside and outside of the tappet, at the taper surface position. Section does not interfere with the oil drain hole. Therefore, it is not necessary to perform secondary processing such as chamfering for the purpose of avoiding sliding wear or deformation on the outer wall side opening peripheral edge of the tappet forming the oil drain hole, so that the number of processing steps can be reduced.

[0010]

An embodiment of the present invention will be described with reference to the drawings. (First Embodiment) A first embodiment in which the fuel supply device of the present invention is applied to a high pressure supply pump for a gasoline engine is shown in FIG. 2, and a state in which the high pressure supply pump of FIG. 2 is mounted on a head cover of a multi-cylinder engine is shown. 3 shows.

The high pressure supply pump 10 is fixed to the head cover 100 with bolts 112. The high pressure supply pump 10 is driven by a cam 111 attached to the valve cam shaft 110 and supplies high pressure fuel to the combustion chamber 113 of each cylinder. As shown in FIG. 2, in the high-pressure supply pump 10, an upper portion of a cylinder 11 accommodating an intake port 12 in which an intake passage 12a is formed, an electromagnetic valve 20, and a delivery valve 30 is a head cover which is a part of an engine housing. Bolt 112 exposed to the outside of 100 and shown in FIG.
Is fixed to the head cover 100. The other part of the high-pressure supply pump 10 housed in the head cover 100 is housed in the housing hole 100 a of the head cover 100 while being surrounded by the cylindrical tappet guide 40. The tappet guide 40 is fixed to the cylinder 11 by a screw screw 60, but in the present invention, a pin can be used instead of the screw screw 60. The cam 111 is attached to a valve cam shaft 110 that opens / closes an intake / exhaust valve (not shown) and drives the high pressure supply pump 10.

Annular fuel reservoirs 11b and 11c are formed on an inner wall 11a of a cylinder 11 which supports a plunger 43, which will be described later, so as to be capable of reciprocating. The fuel reservoir 11b communicates with the intake passage 12a via the return passage 17, and the fuel reservoir 11c communicates with a return passage (not shown). A suction passage 12a is formed in the suction port 12, and fuel is supplied from a low-pressure fuel pump (not shown). The intake passage 12 a communicates with the fuel passage 13 and also communicates with the fuel reservoir 11 b via the return passage 17.

The solenoid valve 20 is vertically inserted into the cylinder 11, and a valve body 22 having a fuel supply passage is formed inside the solenoid valve 20. Valve 2
The valve body 3 is arranged in the valve body 22 so as to be able to contact and separate from the valve seat 21. The lower end surface of the valve body 22 in FIG. 2 is in surface contact with the plate 24, the lower end surface of the plate 24 in FIG. 2 is in contact with the washer 25, and the lower end surface of the washer 25 in FIG. 2 is in surface contact with the cylinder 11. An annular fuel gallery 14 is formed on the inner wall of the cylinder 11 around the electromagnetic valve 20, and the fuel gallery 14 communicates with the fuel passage 13 and the communication passage 26.

The delivery valve 30 is fixed to the cylinder 11 by screw connection, and the discharge valve body 31 is biased to the valve seat 33 by the compression coil spring 32. When the pressure in the pressurizing chamber 16 exceeds a predetermined pressure, the compression coil spring 32
The discharge valve body 31 lifts against the urging force of the discharge passage 1
5 and the discharge port 34 communicate with each other. The delivery valve 30 is connected to a common rail (not shown) by a fuel steel pipe (not shown).

The tappet 41 is formed in a cylindrical shape with a bottom, and a flat surface 41a formed on the outer wall of the bottom of the tappet 41 slides on the cam surface 111a of the cam 111. Tappet 41
Is slidably supported on the inner wall of the tappet guide 40. Lubricating oil is supplied between the inner wall of the tappet guide 40 and the outer wall of the tappet 41 to prevent seizure with the tappet guide 40 due to the reciprocating movement of the tappet 41. When the tappet 41 moves up and down, the head cover 100
Air can flow through a space defined by the cylinder 11, the tappet guide 40, and the tappet 41 through the air passage 101 formed in the.

The plunger 43 is axially slidably supported by the inner wall of the cylinder 11 forming the sliding hole 11a. The spring seat 44 is the compression coil spring 4
5, it is urged downward in FIG. 2 and is in contact with the inner bottom surface of the tappet 41. The head portion 43a of the plunger 43 is
It is sandwiched between the inner bottom surface of the tappet 41 and the spring seat 44, and is urged downward by the spring seat 44 in FIG. The pressurizing chamber 16 is formed by the upper end surface of the plunger 43 in FIG. 2, the inner wall of the cylinder 11, and the end surface of the solenoid valve 20.

The structure of the tappet 41 will be described in detail below. As shown in FIG. 1, the flat surface 4 of the tappet 41
The diameter of 1a is 2D, the width of the cam surface 111a in the axial direction of the camshaft 110 is 2B, the flat surface 41a and the cam surface 11
The sliding distance in the sliding direction with 1a is 2L, the cam 111
The central axis 202 of the cam 111 and the central axis 20 of the flat surface 41a which are orthogonal to the rotation axis of the
1, the eccentric amount in the cam surface width direction is e ₁ , the cam 111
When the eccentric amount in the sliding direction between the central axis 202 of the and the central axis 201 of the flat surface 41a is e ₂ , the following equations are given between the variables.
There is a relationship of (1). The eccentricity e ₁ and the eccentricity e ₂ are
Eccentricity caused by manufacturing error or assembly error of the tappet 41 or the cam 111, or the tappet 41 due to sliding
This is due to the intentional eccentricity for the purpose of rotating.

(B−e ₁ )>D> (L + e ₂ ) ... (1) That is, according to the equation (1), even if the central axis 201 of the flat surface 41a and the central axis 202 of the cam 111 are eccentric, The flat surface 41a is located within the width of the cam surface 111a not including the peripheral edge,
The cam surface 11 is located within the flat surface 41a that does not include the circumference in the sliding direction.
1a slides while making line contact with the flat surface 41a. Here, the flat surface diameter 2D of the tappet 41 and the cam surface width 2B of the cam surface 111a are set as follows.

Based on the static discharge amount Q of the fuel injection pump,
The cam lift L _c and the plunger radius d are determined by the following equation (2). Q = π × d ² × L _c (2) When the cam lift L _c and the plunger radius d are determined, the spring load F _sp for preventing the jumping of the plunger and the tip of the sliding part of the cam on the tappet are used. The cam tip R, which is the radius of curvature at, and the cam surface pressure σd received by the tappet at the sliding portion between the tappet and the cam are examined. The contact length between the flat surface 41a and the cam surface 111a is the shortest at the position ab in FIG. 6, and as can be seen from FIG. 5, the position ab is in the pressure feeding stroke of the plunger.
Normally, the cam surface pressure σd becomes close to the maximum value when the tappet 41 and the cam 111 are in contact with each other at the shortest length in the pressure feeding stroke of the plunger. On the other hand, due to the strength problem between the tappet 41 and the cam 111, the cam surface pressure σd is limited to the limit cam surface pressure σmax.
Is set. Taking into consideration the severest condition in terms of strength, the cam surface pressure σd is set to the maximum value that satisfies σd <σmax and the following equations (3) to (5).

Σd = {Fn × (1 / r ₁ + 1 / r ₂ ) / (Kd × B ₁ )} ^1/2 (3) Kd = (1-ν ₁ ² ) × π / E ₁ + (1-ν ₂ ² ) × π / E ₂ (4) Fn = π × d ² × P + F _sp (5) P: Discharge pressure F _sp : Spring load r ₁ : Cam tip R r ₂ : Bottom surface R of tappet (r ₂ = ∞ in this embodiment) B ₁ : Shortest contact distance between tappet and cam (B ₁ <2
B) [nu _1: cam Material Poisson's ratio E _1: cam Material Young's modulus [nu _2: tappet Material Poisson's ratio E _2: From tappet Material Young's modulus above formula (1) to (5), the flat surface diameter 2D and cam tappet 41 The face width 2B is determined.

According to the tappet 41 and the cam 111 designed to satisfy the expressions (1) to (5), the flat surface diameter 2D of the tappet is larger than the sliding distance 2L between the flat surface 41a and the cam surface 111a. As a result, when the tappet 41 reciprocates with the rotation of the cam 111 as shown in FIGS. 5 and 6, the flat surface 41a and the cam surface 111a are always in linear contact with the contact length B ₁ at the shortest. Further, since the cam surface width 2B is larger than the flat surface diameter 2D, the cam 11
It is prevented that the peripheral portion of 1 contacts the flat surface 41a. Therefore, the peripheral edge of the cam surface 111a can be prevented from being unevenly worn or excessively concentrated in the sliding portion of the tappet 41 with the flat surface 41a due to a processing error, an assembly error, or the like.

Further, as shown in FIG. 4, the oil drain hole 42 is formed on the axial direction of the tapered surface 14b not including the boundary portion with the flat surface 41a so as to communicate the inside and outside of the tappet 41. It is possible to prevent the sliding portion between the flat surface 41a and the cam surface 111a from coming into contact with the oil drain hole 42. Therefore, when forming the oil drain hole 42 in the tappet 41, it is not necessary to form a curved surface around the oil drain hole in order to reduce stress concentration in the sliding portion between the oil drain hole of the tappet 41 and the cam 111. . Further, when forming the oil drain hole 42, it is possible to eliminate secondary processing such as deburring and chamfering that occur in the outer wall side opening of the tappet 41 around the oil drain hole. Further, the burr 111b generated on the peripheral portion of the cam surface 111a is directly connected to the flat portion 41a of the tappet 41.
Since it does not contact the flat surface 41a and the cam surface 111a
It is possible to prevent abrasion of the sliding portion due to the burr 111b, and it is possible to omit the deburring process at the time of manufacturing the cam 111. Further, since the oil drain hole 42 is opened radially outward, it is not necessary to form a notch for releasing oil in the outer peripheral edge portion of the spring seat 44.

Regarding the operation of the high pressure supply pump 10,
(1) Fuel suction process, (2) Fuel pressure-pressurization process will be described separately. (1) Fuel Intake Stroke The cam 111 rotates as the valve camshaft 110 rotates, and the plunger 43 reciprocates together with the tappet 41 and the spring seat 44. When the plunger 43 is located at the upper maximum position in FIG. 2 which is the top dead center, the solenoid valve 2
The power supply to the solenoid (not shown) of 0 is cut off. Then, the valve body 23 is separated from the valve seat 21 by the urging force of the compression coil spring (not shown), and the electromagnetic valve 20 is opened. At this time, the plunger 43 moves downward in FIG. 2 so that the low-pressure fuel discharged from the low-pressure fuel pump causes the suction passage 12a, the fuel passage 13, and the fuel gallery 1 to move.
4, it flows into the pressurizing chamber 16 through the communication passage 26. When the plunger 43 is located at the bottom maximum position in FIG. 2, which is the bottom dead center, the maximum amount of low-pressure fuel flows into the pressurizing chamber 16.

(2) Pressurizing and pressure-feeding stroke of fuel When the plunger 43 reaches a position corresponding to a desired fuel discharge amount in the stroke in which the plunger 43 moves upward from the bottom dead center, an electronic control (not shown) The solenoid of the solenoid valve 20 is energized by the unit. As a result, the valve body 23 moves upward in FIG. 2 and contacts the valve seat 21. That is, the solenoid valve 20 is closed. afterwards,
When the plunger 43 further moves upward in FIG. 2, the fuel in the pressurizing chamber 16 has a high pressure, and the discharge passage 15 and the valve seat 33.
High-pressure fuel is discharged from the delivery valve 30 to the common rail (not shown) through the gap between the discharge valve element 31 and the discharge valve body 31. At this time, part of the high-pressure fuel in the pressurizing chamber 16 may flow into the sliding portion between the plunger 43 and the cylinder 11. The fuel that has flowed in is accumulated in the fuel reservoir 11b shown in FIG. 2, and is returned to the intake passage 12a through the return passage 17. Since the fuel pressure is applied to the suction passage 12a at a low pressure, the fuel sump 11b
The fuel accumulated in the fuel tank may flow downward in FIG. This fuel is collected in the fuel pool 11c and finally returned to the fuel tank through a return passage (not shown), so that the fuel is not mixed with the engine oil.

Next, as compared with Comparative Examples 1 to 4,
The effect of the embodiment will be described. (1) Comparative Example 1 In Comparative Example 1 shown in FIGS. 7 and 8, the bottom outer wall of the tappet 50 is formed only by the flat surface 51 having no tapered surface. Four oil drain holes 52 are formed on the outer peripheral edge of the flat surface 51. In Comparative Example 1, since the taper surface is not formed on the bottom surface of the tappet 50, the flat surface 51 and the cam surface 111a are configured to interfere with the sliding portion between the flat surface 51 and the cam surface 111a and the oil drain hole 52. Extreme wear or deformation may occur at the interference portion between the sliding portion of the oil and the oil drain hole 52.

(2) Comparative Example 2 The comparative example 2 shown in FIG.
2 in order to avoid the interference between 2 and the cam (not shown)
B is made smaller. By reducing the cam surface width, interference with the oil drain hole 52 can be avoided, but by decreasing the minimum contact width B ₁ between the flat surface 51 and the cam surface, the cam surface pressure σd increases. Therefore, problems such as wear or deformation due to stress concentration occur in the sliding portion between the flat surface 51 and the cam surface. Even if the minimum contact width B ₁ is reduced, the diameter of the tappet 50 may be increased in order to prevent the cam surface pressure σd from increasing, but this causes a problem of increasing the size of the high-pressure supply pump.

(3) Comparative Example 3 As shown in FIGS. 10 and 11, the bottom outer wall of the tappet 60 of Comparative Example 3 comprises a flat surface 61 and a tapered surface 62. As shown in FIG. 11, the flat surface diameter 2D is the sliding distance 2L.
Smaller than (D <L + e ₂ ). Therefore, the flat surface 61
The cam 111 may make point contact with the bottom surface of the tappet 60 on the circumference where the taper surface 62 and the taper surface 62 are in contact with each other. Then
Since excessive stress concentration occurs at the point contact portion 120, problems such as wear or deformation of the tappet 60 and the cam 111 occur. In order to prevent wear and deformation, the tappet material may be changed or the bottom surface of the tappet 60 may be hardened by surface treatment. However, in any case, the tappet manufacturing cost increases.

(4) Comparative Example 4 As shown in FIGS. 12 and 13, the oil drain hole 72 is formed through the bottom portion 71 of the tappet 70. In order to allow oil to escape from the inside of the tappet 70 to the outside,
A notch 73a is provided at the outer peripheral edge of the spring seat 73 to form a predetermined gap with the inner surface of the tappet 70. An oil escape groove 71a is formed on the inner wall of the bottom. Further, the bottom outer wall side opening of the oil drain hole 72 is chamfered 72a by secondary processing in order to reduce sliding wear with the cam surface. Therefore, there is a problem that the manufacturing cost increases because the processing man-hour increases.

In comparison with Comparative Examples 1 to 4 described above, in the first embodiment of the present invention, the tappet 41 and the cam 111 are formed so as to satisfy the formula (1), and the tappet 41 is formed.
By forming the taper surface 41d on the outer periphery of the flat surface 41a, it is possible to avoid the interference between the cam surface 111a and the oil hole 42. Therefore, the secondary processing after the oil hole processing, for example, the chamfering of the oil drain hole 42, etc. It is possible to prevent wear and deformation of the tappet 41 around the oil drain hole 42, as well as to eliminate the need for the above process.

Since the cam surface width 2B of the cam surface 111a is larger than the flat surface diameter 2D of the flat surface 41a, the flat surface 4
The minimum contact width B ₁ in the sliding area between 1a and the cam surface 111a can be made as large as possible. Therefore, the cam surface pressure σ
Since d is reduced, wear or deformation of the sliding portion of the tappet 41 and the cam 111 can be reduced.
This eliminates the need to harden the bottom surface of the tappet by changing the material of the tappet or treating the surface of the tappet, thereby reducing the manufacturing cost of the tappet.

By making the flat surface diameter 2D of the flat surface 41a larger than the sliding distance 2L, point contact between the flat surface 41a and the tapered surface 41b and the cam surface 111a can be prevented. As a result, it is possible to prevent wear or deformation due to excessive stress concentration between the tappet 41 and the cam 111. By forming the oil drain hole 42 at the axial position including the tapered surface 41b except for the boundary portion with the flat surface 41a,
Since the opening of the oil drain hole 42 on the cam 111 side does not come into contact with the cam 111, there is no need for secondary processing such as chamfering around the opening of the oil drain hole 42. Further, a notch or the like may be provided on the outer peripheral edge portion of the spring seat 44 or the tappet 4
It is not necessary to provide an oil escape groove on the inner wall of the bottom portion of 1, and the oil is naturally discharged from the oil drain hole 42 to the outside. This facilitates the manufacture of the tappet 41 and the spring seat 43.

(Second Embodiment) A second embodiment of the present invention is shown in FIG.
4 shows. A boundary portion 81a between the flat surface 81 and the tapered surface 82 of the tappet 80 is formed into a smooth curved surface. The oil drain hole 83 is formed at an axial position of the tapered surface 82 including the boundary portion 81a. Therefore, the stress concentration between the bottom surface 81 of the tappet 80 and the cam surface can be further reduced.

(Third Embodiment) A third embodiment of the present invention is shown in FIG.
It is shown in FIG. The flat surface 91 and the outer surface of the tappet 90 are connected by a curved surface 93. The oil drain hole 92 is formed at an axial position of the curved surface 93. Thereby, the stress concentration at the contact portion between the bottom surface of the tappet and the cam surface can be favorably reduced, and the stress concentration at the outer side surface 94 of the tappet 90 and the inner wall surface of the tappet guide can be favorably reduced.

(Fourth Embodiment) A fourth embodiment of the present invention is shown in FIG.
6 is shown. Flat surface 96 formed on the bottom surface of the tappet 95
The bottom portion 98 of the oil drain hole 97 formed on the side wall of the tappet 95 is not formed on the same plane, and the flat surface 9
A step is formed at the connecting portion between 6 and the bottom portion 98. Therefore, the oil drain hole 97 can discharge the oil from the inside to the outside of the tappet 95 without interfering with the cam surface.

In addition to the embodiments of the present invention described above, in the present invention, the bottom surface of the tappet may be entirely flat. Further, in the present invention, the tappet can be formed into a solid cylindrical shape. Further, in the present embodiment, the fuel supply device of the present invention is applied to a high pressure supply pump for a gasoline engine, but the present invention can also be applied to a high pressure supply pump for a diesel engine, and
It can also be applied to a fuel pump for low pressure.

[Brief description of drawings]

FIG. 1 is a bottom view showing a tappet of a high pressure supply pump according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a high-pressure supply pump according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state in which the high pressure supply pump shown in FIG. 2 is attached to an engine head cover.

FIG. 4 is an enlarged view showing the periphery of an oil drain hole of the first embodiment.

FIG. 5 is a front view showing an operating state of the cam and tappet of the first embodiment.

6 is a view on arrow VI in FIG.

FIG. 7 is a front view showing a first comparative example of the first embodiment.

FIG. 8 is a view taken in the direction of the arrow VIII in FIG. 7;

FIG. 9 is a bottom view showing a second comparative example of the first embodiment.

FIG. 10 is a front view showing a comparative example 3 of the first embodiment.

11 is a view taken in the direction of arrow XI in FIG.

FIG. 12 is a bottom view showing a comparative example 4 of the first embodiment.

FIG. 13 is a sectional view taken along line XIII-XIII of FIG.

FIG. 14 is a sectional view showing a main part of a second embodiment of the present invention.

FIG. 15 is a sectional view showing a main part of a third embodiment of the present invention.

FIG. 16 is a sectional view showing a main part of a fourth embodiment of the present invention.

[Explanation of symbols]

 10 High-pressure supply pump (fuel supply device) 41 Tappet 41a Flat surface 41b Tapered surface 80, 90, 95 Tappet 81, 91, 96 Flat surface 82 Tapered surface 83, 92, 97 Oil drain hole

Claims (3)

[Claims] 1. A tappet having a flat surface on the bottom outer wall,
A cam that has a cam surface that slides on the flat surface and that reciprocally drives the tappet according to the rotation of the camshaft, and a plunger that reciprocates together with the tappet, are sucked into the pressurizing chamber as the plunger reciprocates. A fuel supply device for pressurizing and feeding the fuel, wherein the flat surface diameter is 2D, the cam surface width in the axial direction of the cam shaft is 2B, and the flat surface and the cam surface slide in the sliding direction. The distance is 2 L, the eccentric amount in the width direction of the cam surface between the center axis of the cam and the center axis of the flat surface which is orthogonal to the rotation axis of the cam and parallel to the center axis of the flat surface is e ₁ , and the cam is the eccentricity in the sliding direction of the central axis and the center axis of the flat surface when the e ₂ of the fuel supply apparatus characterized by satisfying _{(B-e 1)> D} > (L + e 2). 2. The fuel supply device according to claim 1, wherein a taper surface is formed on the outer periphery of the flat surface in a direction away from the cam as it goes radially outward. 3. The tappet is formed in a bottomed cylindrical shape,
3. The fuel supply device according to claim 2, wherein an oil drain hole communicating between the inside and outside of the tappet is formed at the tapered surface position.