JP5533740B2 - High pressure fuel pump - Google Patents

Description

  The present invention relates to a high-pressure fuel pump that supplies high-pressure fuel to an internal combustion engine, and relates to a high-pressure fuel pump that pressurizes fuel by reciprocating a plunger as the camshaft rotates to increase the pressure.

[Conventional technology]
Conventionally, a plurality of high-pressure fuel pumps that supply high-pressure fuel to an internal combustion engine (engine) such as a diesel engine are arranged radially in the circumferential direction of the cam chamber of the pump housing as shown in FIGS. A plurality of plungers, a cam 101 that reciprocally drives these plungers in the axial direction thereof, a camshaft having two journals 102 and 103 provided on both sides in the rotational axis direction of the cam 101, and a plurality of rotational movements of the cam 101. 2. Description of the Related Art A supply pump including a cam ring for converting the plunger into a reciprocating motion of the plunger and housings 104 and 105 having bearing sleeves surrounding the two journals 102 and 103 is known (see, for example, Patent Documents 1 to 3). The cam 101 is integrally formed with an eccentricity with respect to the rotation axis of the camshaft.
In such a supply pump, a cam ring that revolves around the cam 101 as the cam shaft rotates (eccentric operation of the cam 101) reciprocally drives each plunger inserted in the cylinder holes of a plurality of cylinders. Each plunger is configured to pressurize the fuel in the pressurizing chamber to increase the pressure, and supply the pressure to the engine side.

Further, when the camshaft rotates at high speed, there is a possibility that the cam 101 of the camshaft and the cam ring may be seized, so that the metal bush 111 is installed between the cam 101 of the camshaft and the cam ring. A part of the fuel is supplied as lubricating oil between the cam 101 of the camshaft and the metal bush 111, and seizure is suppressed by an oil film formed between the cam 101 and the metal bush 111.
Further, if the camshaft rotates at a high speed, the camshaft journals 102 and 103 and the bearing sleeves of the housings 104 and 105 may be seized, so that the camshaft journals 102 and 103 and the housings 104 and 105 Metal bushes 112 and 113 are installed between the bearing sleeves. A part of the fuel is supplied as lubricating oil between each journal 102, 103 and each metal bush 112, 113 of the camshaft, and is formed between each journal 102, 103 and each metal bush 112, 113. The oil film suppresses seizure.

By the way, in the case of a supply pump that reciprocally drives the plunger in accordance with the eccentric operation of the cam 101 of the camshaft and pressurizes and pressure-feeds the fuel, as shown in FIG. The above loads (plunger driving force and driving reaction force) act as concentrated loads on the camshaft cam 101, and the camshaft may be bent and deformed in an arcuate shape.
In this case, excessive surface pressure (high surface pressure F) acts on the cam contact portion of the metal bush 111 that receives stress (radial load) from the cam 101 of the camshaft. In each metal bush 111, a high surface pressure F is applied to a portion facing the central portion of the cam 101 on which the concentrated load acts.
Also, as shown in FIGS. 15B and 15C, excessive surface pressure (at the journal contact portion of each metal bush 112, 113 that receives stress (radial load) from each journal 102, 103 of the camshaft. High surface pressure) F acts. In each of the metal bushes 112 and 113, a high surface pressure F is applied to a portion on the side closer to the cam 101.

Here, in the case of a supply pump that is used with a load of a certain value or more, that is, in a state where it receives a concentrated load accompanying the pressure and pressure feeding of each plunger, the radius of curvature of the camshaft cam 101 and the metal bush Although the radius of curvature of the inner circumference of 111 differs in the initial state, the radius of curvature of the outer circumference of the cam 101 and the radius of curvature of the inner circumference of the metal bush 111 gradually approach each other during use. This is referred to as the “familiar process”. At this time, the inner peripheral portion of the metal bush 111 is cut so as to have a curvature radius similar to that of the cam 101.
In the case of a supply pump, the radius of curvature of the outer circumference of each journal 102, 103 of the camshaft and the radius of curvature of the inner circumference of each metal bush 112, 113 are different in the initial state shown in FIG. During use, the radius of curvature of the outer circumference of each journal 102, 103 and the radius of curvature of the inner circumference of each metal bush 112, 113 gradually approach each other, which is referred to as an “initial familiarization process”. At this time, the inner peripheral part of each metal bush 112,113 is shaved so that it may become a curvature radius comparable as the curvature radius of each journal 102,103.

  As described above, in the case of a supply pump that is used with a load of a certain value or more, fuel is supplied between the camshaft cam 101 and the metal bushing 111 in order to prevent seizure in the initial running-in process. An oil film is formed between the journals 102 and 103 of the camshaft and the metal bushes 112 and 113, and fuel is supplied between the journals 102 and 103 and the metal bushes 112 and 113. Even if an oil film is formed between the cam contact portion of the metal bush 111 and the journal contact portions of the metal bushes 112 and 113 in the initial conforming process, excessive surface pressure (high surface pressure) F Works. As a result, the oil film formed between the camshaft cam 101 and the metal bush 111 or the oil film formed between the camshaft journals 102 and 103 and the metal bushes 112 and 113 is cut. The amount of wear of the bushes 111 to 113 is very large (see FIG. 16B).

Here, when the oil film formed between the cam 101 of the camshaft and the metal bush 111 is cut, the convex curved surface of the cam 101 and the concave curved surface of the metal bush 111 come into curved contact. When the oil film formed between each journal 102, 103 of the camshaft and each metal bush 112, 113 is cut, the convex curved surface of each journal 102, 103 and the concave curved surface of each metal bush 112, 113 are curved. Contact.
As a result, the pressure receiving area of the cam contact portion of the metal bush 111 that receives a radial load from the cam 101 of the cam shaft, and the cam contact portion of each of the metal bushes 112 and 113 that receives the radial load from the journals 102 and 103 of the cam shaft. Since the pressure receiving area increases, the contact surface pressure between the cam 101 of the camshaft and the metal bush 111 and the contact surface pressure between the journals 102 and 103 of the camshaft and the metal bushes 112 and 113 decrease.
As a result, fuel as lubricating oil easily enters the sliding portion between the cam shaft cam 101 and the metal bush 111 and the sliding portion between the cam shaft journals 102 and 103 and the metal bush 112 and 113. An oil film is formed on the sliding portion between the cam 101 and the metal bush 111 and the sliding portion between each journal 102 and 103 of the cam shaft and each metal bush 112 and 113.

[Conventional technical problems]
Incidentally, in recent years, there has been a demand for further increase in fuel injection pressure for the purpose of improving engine output and reducing emissions of NOx, black smoke and the like discharged from the engine. However, in order to increase the fuel injection pressure, it is necessary to increase the pressurized pressure of the fuel by the high pressure fuel pump and increase the pressure of the fuel discharged from the high pressure fuel pump.
When the pressure of the fuel is increased, the load accompanying the pressure and pressure feeding of each plunger becomes excessive. In particular, the sliding portion between the cam 101 of the cam shaft and the metal bush 111, the journals 102 and 103 of the cam shaft, and the metal bush 112 , 113 generates a large surface pressure (F) at the sliding portion.

As described above, when the supply pump is used at a high load of a certain value or more, the wear amount of the metal bushes 111 to 113 generated in the initial running-in process becomes very large. The problem that the possibility that it will reach becomes high occurs.
Further, there is a problem that seizure of sliding portions between the cam shaft cam 101 and the metal bush 111 and sliding portions between the cam shaft journals 102 and 103 and the metal bushes 112 and 113 occurs.

JP 2008-184953 A JP 2010-223177 A JP 2010-223181 A

  An object of the present invention is to provide a high-pressure fuel pump capable of preventing wear and seizure of a sliding portion between a camshaft and a bearing member. Another object of the present invention is to provide a high-pressure fuel pump that can reduce the amount of wear of a bearing member. Another object of the present invention is to provide a high-pressure fuel pump that can prevent adhesive wear of bearing members. It is another object of the present invention to provide a high-pressure fuel pump that can improve the seizure resistance of the sliding portion between the camshaft and the bearing member.

The invention (high pressure fuel pump) described in claim 1 is a piston (1-3) that reciprocates in a cylinder hole to pressurize and feed fuel, and the piston (1-3) is moved in the moving direction (reciprocating). ) A camshaft (4-6) to be driven, a block (11-13) having an accommodation hole for accommodating the camshaft (4-6) so as to be movable in the rotational direction, and accommodation of the block (11-13) Cylindrical bearing members (7-9) fixed to the hole wall surface and supporting the camshafts (4-6) so as to be slidable in the rotational direction are provided.
Thus, when the bearing member receives a load (driving force or driving reaction force of the piston) from the camshaft (4 to 6), an excessive surface pressure (high pressure) is applied to the contact portion with the camshaft (4 to 6). Surface pressure).
Therefore, between the blocks (11-13) and the bearing members (7-9), the bearing members (7-9) receive a load from the camshafts (4-6) and generate a high surface pressure. ) Is provided to allow deformation.

In particular, according to the first aspect of the present invention, the deformation of the bearing member (7-9) in a direction in which a high surface pressure (excessive surface pressure) is generated by receiving a load from the camshaft (4-6). Bearing members (7-9) are provided by forming clearances (S1 to S3) between the blocks (11-13) and the bearing members (7-9). Therefore, it is possible to ensure the deformation allowance of the bearing members (7 to 9). That is, the bearing members (7-9) can be easily deformed in a direction in which a high surface pressure is generated by receiving a load from the camshafts (4-6).
As a result, the bearing members (7-9) receive a load from the camshafts (4-6), and the surface pressure between the camshafts (4-6) and the bearing members (7-9) is locally high. Even if it becomes, since it becomes possible to increase the pressure receiving area of the bearing member (7-9) by the deformation of the bearing member (7-9), the camshaft (4-6) and the bearing member (7-9) It is possible to reduce the surface pressure between the two.
As a result, it is possible to prevent wear and seizure of the sliding portion between the camshaft (4-6) and the bearing member (7-9). Moreover, the amount of wear of the bearing members (7-9) can be significantly reduced. Moreover, the adhesion wear of a bearing member (7-9) can be reduced. In addition, since the seizure resistance of the sliding portion between the camshaft (4-6) and the bearing member (7-9) can be improved, the durability of the high-pressure fuel pump can be improved.

According to invention of Claim 2, the outer surface of the bearing member (7-9) of the direction which receives a load from a camshaft (4-6) and a high surface pressure generate | occur | produces is dented to the camshaft side. The clearances (S1 to S3) that allow the deformation of the bearing members (7 to 9) are provided.
According to invention of Claim 3, a deformation | transformation relief groove (64-66) is provided in the outer surface of the bearing member (7-9) of the direction which receives a load from a camshaft (4-6) and a high surface pressure generate | occur | produces. By forming the gaps, gaps (S1 to S3) that allow deformation of the bearing members (7 to 9) are provided.
The direction in which high surface pressure is generated by receiving a load from the camshafts (4 to 6) refers to the load (piston driving force or driving reaction force) that accompanies the pressurization and pressure feeding of the pistons (1 to 3). A direction acting as a load (stress) on the shafts (4 to 6), or a direction opposite to this direction (an opposite direction) by 180 °.

According to invention of Claim 4, it has two crossing ridgelines of a deformation | transformation escape groove (64-66) and the outer surface of a bearing member (7-9) in the circumferential direction of a bearing member (7-9). ing. A flat planar bottom is formed between the two intersecting ridge lines.
In addition, generally the outer peripheral surface of the convex-curved shape which has a predetermined curvature radius is formed in the outer surface of a bearing member (7-9). Therefore, a plane extending in a direction perpendicular to the vertical plane of the central axis of the bearing member (7-9) by cutting out (shaving) a part of the outer peripheral surface of the convex curved shape of the bearing member (7-9). A shaped bottom may be formed.

According to invention of Claim 5, it has two crossing ridgelines of a deformation | transformation escape groove (64-66) and the outer surface of a bearing member (7-9) in the circumferential direction of a bearing member (7-9). ing. A curved curved bottom surface is formed between the two intersecting ridge lines. In this case, the contact surface pressure between the camshaft (4 to 6) and the bearing member (7 to 9) is made uniform as compared with the case where the bottom surface of the deformation escape groove (64 to 66) is formed only by a flat surface. It is possible to escape.
A convex curved surface having a radius of curvature larger than the radius of curvature of the convex curved surface of the bearing member (7-9), that is, a gentle convex curved surface, on a part of the outer peripheral surface of the convex curved shape of the bearing member (7-9). A shaped bottom may be formed. Moreover, you may provide a plane and a curved surface in the bottom face of a deformation | transformation escape groove (64-66).

According to invention of Claim 6, the bottom face of a deformation | transformation escape groove (64-66) is the other end from the one end of the axial direction (the same direction as the rotating shaft direction of a camshaft) of a bearing member (7-9), or It inclines with respect to the axial direction of a bearing member (7-9) so that it may become an upward slope toward the center.
According to the seventh aspect of the present invention, the bottom surfaces of the deformation relief grooves (64 to 66) extend from both ends in the axial direction of the bearing members (7 to 9) (the same direction as the rotational axis direction of the camshaft) from the both ends toward the center. The bearing members (7 to 9) are inclined with respect to the axial direction so as to have an upward slope. In this case, it is not necessary to distinguish the orientation of the bearing members (7-9) with respect to the blocks (11-13), and workability when the bearing members (7-9) are assembled to the wall surfaces of the housing holes of the blocks (11-13). (Assembly workability) can be improved.

According to the eighth aspect of the present invention, the housing hole wall surface of the block (11-13) is opposite to the camshaft side in a direction in which a high surface pressure is generated by receiving a load from the camshaft (4-6). By denting it to the side, gaps (S1 to S3) that allow deformation of the bearing members (7 to 9) are provided.
According to the invention described in claim 9, between the block (11-13) and the bearing member (7-9) in a direction not receiving a load from the camshaft (4-6) and generating no high surface pressure. Only, clearances (S1 to S3) permitting deformation of the bearing members (7 to 9) by sandwiching restriction parts (81 to 83) for restricting deformation of the bearing members (7 to 9) to the block side. ) Is provided.

According to the invention described in claim 10 and claim 11 , the bearing member (7 to 9) receives a load from the camshaft (4 to 6) (and generates a high surface pressure) ( 61-63). Moreover, the deformation | transformation escape part which accept | permits a deformation | transformation of a bearing member (7-9) is provided only in the back side of the high surface pressure generation | occurrence | production part (61-63) of a bearing member (7-9).
According to the invention described in claim 12, the cam (4) having a circular cross section is provided on the camshaft (5, 6). The cam (4) is provided on the camshaft (5, 6) so as to be eccentric with respect to the rotational axis direction of the camshaft (5, 6).
According to the invention described in claim 13, the block is a cam ring (11) that revolves around the cam (4). The accommodation hole is a cam accommodation hole for rotatably accommodating the cam (4).
According to the invention described in claim 14, the piston is a plunger (1-3) that contacts the outer surface of the cam ring (11) and reciprocates following the revolution of the cam ring (11).

According to the fifteenth aspect of the present invention, the two journals (5, 6) are provided on both sides of the camshaft cam (4) in the rotation axis direction.
According to the invention described in claim 16, the block is the housing (12, 13) in which the cam chamber (20) is formed.
The accommodation hole is a journal accommodation hole that rotatably accommodates at least one of the two journals (5, 6).
In addition, a plurality of cylinders and plungers (pistons) are provided radially around the cam chamber (20) of the housing (12, 13) (and at a predetermined angular interval in the circumferential direction of the cam chamber). The cylinder and the plunger (piston) constitute a high-pressure fuel pump body (pump element).

According to invention of Claim 17, the deformation | transformation relief which accept | permits a deformation | transformation of a bearing member (7-9) by inserting | pinching an elastic body between a block (11-13) and a bearing member (7-9). Parts are provided.
According to the eighteenth aspect of the present invention, the lubricating oil supply means (such as a lubricating oil supply flow path) for supplying lubricating oil to the sliding portion between the camshaft (4-6) and the bearing member (7-9) is provided. I have. As a result, the lubricating oil can easily enter the sliding portion between the camshaft (4-6) and the bearing member (7-9), so the sliding between the camshaft (4-6) and the bearing member (7-9) Since the oil film is efficiently formed on the moving portion, the sliding portion between the camshaft (4-6) and the bearing member (7-9) is lubricated.
As a result, the wear resistance and seizure resistance of the sliding portion between the camshaft (4-6) and the bearing member (7-9) can be improved, so that the durability of the high-pressure fuel pump can be improved.

It is sectional drawing which showed the camshaft bearing structure of the high pressure fuel pump (Example 1). It is sectional drawing which showed the camshaft bearing structure of the high pressure fuel pump (Example 1). (A) is sectional drawing which showed the cam bearing structure of the camshaft, (b) is sectional drawing which showed the journal bearing structure of the camshaft (Example 1). (A)-(c) is the longitudinal cross-sectional view which showed the modification of the metal bush (Example 1). (A) is the longitudinal cross-sectional view which showed the modification of the metal bush, (b) is AA sectional drawing (transverse sectional view) of (a) (Example 1). (A) is the longitudinal cross-sectional view which showed the modification of the metal bush, (b)-(d) is BB sectional drawing (transverse sectional view) of (a) (Example 1). (A) is the longitudinal cross-sectional view which showed the modification of the metal bush, (b)-(d) is CC sectional drawing (transverse sectional view) of (a) (Example 1). (A) is sectional drawing which showed the cam bearing structure of the camshaft, (b) is sectional drawing which showed the journal bearing structure of the camshaft (Example 2). (A) is sectional drawing which showed the cam bearing structure of the camshaft, (b) is sectional drawing which showed the journal bearing structure of the camshaft (Example 3). (Example 4) which is sectional drawing which showed the camshaft bearing structure of the high pressure fuel pump. (Example 4) which is DD sectional drawing of FIG. (A) is sectional drawing which showed the cam bearing structure of the camshaft, (b) is sectional drawing which showed the journal bearing structure of the camshaft (Example 4). (A) is sectional drawing which showed the cam bearing structure of the camshaft, (b) is sectional drawing which showed the journal bearing structure of the camshaft (Example 5). (A) is sectional drawing which showed the cam bearing structure of the camshaft, (b) is sectional drawing which showed the journal bearing structure of the camshaft (Example 6). (A) is a schematic diagram explaining that an excessive surface pressure (high surface pressure) is generated at a portion where a radial load acts on the metal bush, and (b) and (c) are surface pressure distributions acting on the metal bush. It is the figure which showed (conventional technique). (A), (b) is the schematic diagram explaining that a metal bush wears in order to match | combine a curvature radius in an initial conforming process (conventional technique).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
An object of the present invention is to prevent wear and seizure of a sliding portion between a camshaft and a bearing member, and to reduce the amount of wear of the bearing member and prevent adhesive wear of the bearing member. The purpose of improving the seizure resistance of the sliding part with the bearing member is to improve the bearing member in a direction in which a high surface pressure is generated by receiving a load (stress) from the camshaft between the block and the bearing member. This was realized by providing a deformation relief part to allow deformation.
In particular, the deformation relief portion is provided by forming a gap between the block and the bearing member. The deformation relief portion is provided by sandwiching an elastic body between the block and the bearing member.
Here, there is provided lubricating oil supply means such as a lubricating oil supply flow path for supplying fuel as lubricating oil to the sliding portion between the camshaft and the bearing member. As a result, lubricating oil can easily enter the sliding portion between the camshaft and the bearing member, so that an oil film is efficiently formed on the sliding portion between the camshaft and the bearing member, and the sliding portion between the camshaft and the bearing member. The wear resistance and seizure resistance of the material are further improved.

[Configuration of Example 1]
FIGS. 1 to 7 show a first embodiment of the present invention, and FIGS. 1 and 2 show a camshaft bearing structure of a high-pressure fuel pump.

A fuel supply device for an internal combustion engine according to the present embodiment is mounted in an engine room of a vehicle such as an automobile. For example, a common rail known as a fuel injection system for an internal combustion engine (engine) such as a diesel engine having a plurality of cylinders. It is comprised by the type fuel injection system (accumulation type fuel injection device). The common rail fuel injection system includes a common rail that accumulates high-pressure fuel, and a plurality of injectors (solenoid injectors or piezo injectors) that inject the high-pressure fuel accumulated in the common rail into the combustion chamber of each cylinder of the engine. A high-pressure fuel pump that pressurizes the fuel to increase the pressure.
Here, the power supplied to the actuator that opens and closes each needle valve of the plurality of injectors is configured to be controlled by an engine control unit (ECU).

The high-pressure fuel pump includes a plurality of (three) plungers 1 to 3 that reciprocate in the axial direction and pressurize and pressure-feed fuel, and a camshaft (excen cam 4, journal) that drives the plungers 1 to 3 in the reciprocating direction. 5, 6), a cylindrical metal bush 7 installed so as to surround the periphery of the cam 4 of the camshaft, and the journals 5, 6 of the camshaft so as to surround the periphery of the camshaft. Cylindrical metal bushes 8 and 9 and an oil seal 10 installed, a block (cam ring 11 and housings 12 and 13) having bearing sleeves surrounding each of the metal bushes 7 to 9 in the circumferential direction, and plungers 1 to 1 Coil springs 14 to 16 for generating a load (pressing load) for pressing 3 against each seating surface of the cam ring 11, and plungers 1 to 1 Fuel as lubricant is supplied from a cylinder body 17 to 19 having a cylindrical cylinder that slidably supports the cylinder in a reciprocating direction and a feed pump as a lubricant supply means via a lubricant supply channel. The cam chamber 20 is provided.
Here, the oil seal 10 seals an annular gap between the outer periphery of the camshaft journal 6 and the inner periphery of the bearing sleeve of the housing 13.

The high pressure fuel pump is composed of a plurality of (three) pump elements (plungers 1 to 3 and cylinder bodies 17 to 19) radially about a cam chamber 20 formed inside the housings 12 and 13. A fuel pump body) is provided. These pump elements are installed in the circumferential direction of the cam chamber 20 at predetermined angular intervals (for example, 120 ° equal intervals).
Here, the bearing sleeve of the cam ring 11 is a cylindrical bearing holder that houses the cam 4 of the camshaft so as to be movable (rotatable) in the rotational direction.
The bearing sleeves of the housings 12 and 13 are cylindrical bearing holders in which the journals 5 and 6 are accommodated so as to be movable (rotatable) in the rotation direction. An inner rotor 22 and an outer rotor 23 of the feed pump are accommodated in the pump cover 21 attached to the housing 12.

The camshaft has a cam 4 at an intermediate portion in the rotation axis direction, and journals 5 and 6 on both sides of the cam 4 in the rotation axis direction. The journals 5 and 6 of the camshaft are rotatably supported by bearing holders of the housings 12 and 13 through metal bushes 8 and 9, respectively.
A drive pulley (not shown) driven by a belt by a crank pulley coupled to an engine crankshaft is attached to the outer periphery of one end (tip) of the camshaft in the rotation axis direction. Thereby, the camshaft is rotationally driven by the crankshaft of the engine.
An inner rotor 22 of the feed pump is attached to the outer periphery of the other end (rear end) of the camshaft in the rotation axis direction. The feed pump is a low-pressure fuel pump that pumps low-pressure fuel from a fuel tank on the low-pressure side of the fuel system.

Cylindrical cylinders that support the plungers 1 to 3 so as to be slidable in the reciprocating direction are integrated with the cylinder bodies 17 to 19 that are fastened and fixed (fastened and fixed) to the housings 12 and 13 using fastening bolts or the like. Provided. Cylinder holes 27 to 29 in which the sliding surfaces of the plungers 1 to 3 can reciprocate are formed inside the cylinder.
Fuel pressurizing chambers 31 to 33 for pressurizing fuel by reciprocating movement of the plungers 1 to 3 are formed on one side of the cylinder holes 27 to 29 in the axial direction. The cylinder bodies 17 to 19 have fuel intake valves 34 to 36 for opening and closing the fuel supply passages, fuel discharge valves 37 to 39 for opening and closing the fuel discharge passages, and discharge ports (fuel holes) inside. The outlets 41 to 43 are installed.

Here, in the middle of the fuel supply flow path from the feed pump to each of the fuel intake valves 34 to 36, one electromagnetic fuel metering valve (solenoid valve) for adjusting the intake fuel amount is attached. The power supplied to the electromagnetic fuel metering valve is configured to be controlled by the ECU. Thereby, the fuel discharge amount discharged from the outlets 41 to 43 of the high-pressure fuel pump is controlled.
The fuel intake valves 34 to 36 are valves that open and close fuel supply passages for supplying fuel from the electromagnetic fuel metering valves to the fuel pressurizing chambers 31 to 33, and a return that urges the valves in the valve closing direction. A spring, a plug that hermetically closes the opening of each cylinder body 17-19, a valve body that is sandwiched between each cylinder body 17-19 and each plug, and the like.
The fuel discharge valves 37 to 39 are valves that open and close a fuel discharge passage for pumping (discharging) high-pressure fuel from the fuel pressurizing chambers 31 to 33 to the common rail side, and a return that urges the valve in the valve closing direction. A spring and a spring seat for receiving the load of the return spring are used.

Here, the fuel supply flow path for sucking fuel into the fuel pressurizing chambers 31 to 33 from the feed pump via the electromagnetic fuel metering valve and the fuel suction valves 34 to 36 includes a housing 13, a cylinder The body 17-19 and the fuel intake valves 34-36 are constituted by respective fuel flow paths including fuel holes formed in the valve bodies.
Moreover, the high pressure fuel pressurized by the internal volume of each fuel pressurizing chamber 31-33 expanding and contracting with the reciprocating movement of the plungers 1-3 is a spring of the cylinder bodies 17-19 and the fuel discharge valves 37-39. It is comprised by each fuel flow path which consists of a fuel hole etc. which are formed in a seat and outlet 41-43 inside.

The plungers 1 to 3 are columnar pistons extending in the axial direction of the cylinder holes 27 to 29 of the cylinder bodies 17 to 19, and can reciprocate in the cylinder holes 27 to 29 of the cylinder bodies 17 to 19. Has been inserted. The plungers 1 to 3 reciprocate linearly between the top dead center and the bottom dead center following the revolution of the cam ring 11 with the eccentric operation of the cam ring 11. As a result, when the plungers 1 to 3 are lowered and the fuel pressure in the fuel pressurizing chambers 31 to 33 is decreased, the fuel discharge valves 37 to 39 are closed and the fuel intake valves 34 to 36 are opened to electromagnetically. The fuel metered by the fuel metering valve is sucked into the fuel pressurizing chambers 31-33.
Conversely, when the plungers 1 to 3 are raised and the fuel pressure in the fuel pressurizing chambers 31 to 33 reaches a predetermined pressure, the fuel discharge valves 37 to 39 are opened and the fuel pressurizing chambers 31 to 33 are opened. The pressurized high-pressure fuel is pumped and supplied to the common rail through the fuel discharge passage (fuel hole) and the fuel pipe.

Here, a cam chamber 20 to which fuel as lubricating oil is supplied from a feed pump is formed inside the housings 12 and 13. Both ends of the cam chamber 20 are closed by the cylinder bodies 17-19, respectively. The cam chamber 20 accommodates a cam 4, a cam ring 11, a metal bush 7, and coil springs 14 to 16.
The cam chamber side end in the axial direction of each of the plungers 1 to 3 is opposed to the outer surface (a plane formed linearly) of the cam ring 11 disposed so as to surround the periphery of the cam 4 in the circumferential direction. The tappets 44 to 46 are arranged integrally. These tappets 44 to 46 protrude into the cam chamber 20 from the cylinder holes 27 to 29 of the cylinder bodies 17 to 19. The tappets 44 to 46 are the largest outer diameter portions having the largest outer diameter among the plungers 1 to 3.

Here, a cam 4 having a circular cross section perpendicular to the rotation axis direction of the camshaft journals 5 and 6 is eccentrically integrated with the rotation axis direction of the camshaft at an intermediate portion in the rotation axis direction of the camshaft. Is formed.
The cam ring 11 revolves around the cam 4 of the cam shaft. The cam ring 11 is slidably held on the outer periphery of the cam 4 via a metal bush 7. Plungers 1 to 3 that reciprocate following the revolution of the cam ring 11 are arranged on both sides (upper and lower sides) of the cam ring 11.
A bearing holder that surrounds the periphery of the cam 4 of the cam shaft in the circumferential direction is integrally formed on the inner peripheral portion of the cam ring 11. A cam housing hole 47 extending in the direction of the rotation axis of the cam 4 is formed inside the bearing holder. The cam accommodation hole 47 is a shaft accommodation hole for rotatably accommodating the cam 4 of the camshaft.

Here, the housing member of the high-pressure fuel pump includes the housings 12 and 13 and the cylinder bodies 17 to 19.
The housing 12 is a pump housing (housing main body) that rotatably supports the camshaft journal 5 via the metal bush 8.
The housing 13 is a bearing cover (bearing cover) that rotatably supports the journal 6 of the camshaft via the metal bush 9.
The housings 12 and 13 are integrally formed with bearing holders surrounding the journals 5 and 6 of the camshaft in the circumferential direction. Inside these bearing holders, journal receiving holes 48 and 49 extending in the direction of the rotation axis of the respective journals 5 and 6 are formed. These journal accommodating holes 48 and 49 are shaft accommodating holes for rotatably accommodating the respective journals 5 and 6 of the camshaft.

Here, on the outer peripheral surface of the cam ring 11, planar seat surfaces 51 to 53 for receiving a driving reaction force (fuel pressurization load) from the plungers 1 to 3 are provided. These seat surfaces 51 to 53 also have a function as a spring seat portion that receives the reaction force (pressing load) of the coil springs 14 to 16.
The coil springs 14 to 16 urge the tappets 44 to 46 of the plungers 1 to 3 in the direction in which they are pressed against the outer surface of the cam ring 11. That is, the tappets 44 to 46 are pressed against the seat surfaces 51 to 53 of the cam ring 11 by the urging forces (pressing loads) of the coil springs 14 to 16.
In addition, each of the tappets 44 to 46 of the plungers 1 to 3 has a flat contact surface with the seating surfaces 51 to 53 of the cam ring 11. Thereby, since rotation of the cam ring 11 is prevented, the cam ring 11 revolves without rotating while sliding with the tappets 44 to 46 of the plungers 1 to 3 as the cam 4 rotates.

Further, if the camshaft rotates at a high speed, the cam 4 and the cam ring 11 may be seized. Therefore, a cylindrical metal bush 7 is installed between the cam 4 of the cam shaft and the bearing sleeve of the cam ring 11. Yes.
Further, if the camshaft rotates at high speed, the camshaft journals 5 and 6 and the housings 12 and 13 may be seized. Therefore, the camshaft journals 5 and 6 and the bearing sleeves of the housings 12 and 13 Cylindrical metal bushes 8 and 9 are installed between them.

  Note that the fuel in the cam chamber 20 is supplied between the cam 4 of the cam shaft and the metal bush 7 as lubricating oil. As a result, an oil film is formed between the sliding surface of the cam 4 and the sliding surface of the metal bush 7 to suppress seizure of the sliding portion between the cam 4 and the metal bush 7. Further, between the journals 5 and 6 of the camshaft and the metal bushes 8 and 9, for example, fuel is supplied as lubricating oil from the cam chamber 20 or a feed pump. Thereby, the sliding part of each journal 5, 6 and each metal bush 8, 9 is seized between the sliding surface of each journal 5, 6 of the camshaft and the sliding surface of each metal bush 8, 9. An oil film is formed to suppress the above.

  The metal bush 7 is a sintered part (bearing member, bearing) obtained by sintering a metal such as copper or iron, and is formed in a cylindrical shape. The metal bush 7 is press-fitted and fixed to the inner peripheral surface of the bearing holder of the cam ring 11 (the hole wall surface of the cam housing hole 47). A sliding hole 54 is formed inside the metal bush 7 to pivotally support the cam 4 of the camshaft so as to be slidable in the rotational direction. The cam 4 is placed between the outer peripheral surface (sliding surface) of the cam 4 of the camshaft and the hole wall surface (sliding surface, inner peripheral surface) of the sliding hole 54 of the metal bush 7. A sliding clearance for smooth rotation is formed.

  Similar to the metal bush 7, the metal bush 8 is a sintered part (bearing member, bearing) obtained by sintering a metal such as copper or iron, and is formed in a cylindrical shape. The metal bush 8 is press-fitted and fixed to the inner peripheral surface of the bearing holder of the housing 12 (hole wall surface of the journal housing hole 48). In addition, a sliding hole 55 is formed in the metal bush 8 to support the camshaft journal 5 so as to be slidable in the rotational direction. The journal 5 is placed between the outer peripheral surface (sliding surface) of the journal 5 of the camshaft and the hole wall surface (sliding surface, inner peripheral surface) of the sliding hole 55 of the metal bush 8. A sliding clearance for smooth rotation is formed.

  Similarly to the metal bushes 7 and 8, the metal bush 9 is a sintered part (bearing member, bearing) obtained by sintering a metal such as copper or iron, and is formed in a cylindrical shape. Similar to the metal bush 8, the metal bush 9 is press-fitted and fixed to the inner peripheral surface of the bearing holder of the housing 13 (hole wall surface of the journal housing hole 49). A sliding hole 56 is formed in the metal bush 9 to pivotally support the camshaft journal 6 so as to be slidable in the rotational direction. The journal 6 is placed between the outer peripheral surface (sliding surface) of the journal 6 of the camshaft and the hole wall surface (sliding surface, inner peripheral surface) of the sliding hole 56 of the metal bush 9. A sliding clearance for smooth rotation is formed.

Here, as shown in FIG. 3, the metal bushes 7 to 9 are arranged on the sliding portions (sliding contact surface side) between the camshaft cam 4 and the journals 5 and 6, and the camshaft cam 4 and each journal. 5 and 6 are provided with high surface pressure generators 61 to 63 that receive a radial load (driving force and driving reaction force of the plungers 1 to 3 and concentrated load) and generate excessive surface pressure (high surface pressure F). .
In the high-pressure fuel pump of this embodiment, the cam ring 11 and each housing are used for the purpose of preventing wear and seizure of the sliding portion between the cam 4 of the cam shaft and the journals 5 and 6 and the metal bushes 7-9. 12, 13 and the metal bushes 7 to 9, the deformation of the metal bushes 7 to 9 in the direction in which a high surface pressure F is generated by receiving a radial load from the cam 4 of the camshaft and the journals 5 and 6. A deformation relief for allowing is provided.

The deformation relief portions of the metal bushes 7 to 9 are provided by forming a plurality (three) of gaps S1 to S3 between the cam ring 11, the housings 12 and 13, and the metal bushes 7 to 9.
The plurality of gaps S1 to S3 are the outer peripheral surfaces of the metal bushes 7 to 9 in the direction in which the radial load is generated from the cam 4 of the camshaft and the journals 5 and 6, that is, the high surface pressure generating portion 61. ˜63 are provided by denting the back surface of the camshaft side. Specifically, a plurality of gaps S1 to S3 are provided by forming deformation relief grooves (recesses) 64 to 66 on the back side of the high surface pressure generating parts 61 to 63.
On both sides of the deformation escape grooves 64 to 66 in the groove width direction, intersecting ridgelines EL1 and EL2 between the bottom surfaces of the deformation escape grooves 64 to 66 and the outer peripheral surfaces (convex curved surfaces 67 to 69) of the metal bushes 7 to 9 are respectively provided. ing. The two intersecting ridgelines EL1 and EL2 are provided at equal intervals in the circumferential direction of the metal bush 7.
The bottom surfaces of the deformation relief grooves 64 to 66 are flat planar bottom surfaces and are planar end surfaces (outer surfaces) formed between the two intersecting ridge lines EL1 and EL2.

Here, on the outer peripheral surfaces of the metal bushes 7 to 9, convex curved outer peripheral surfaces (convex curved surfaces 67 to 69) having a predetermined radius of curvature are formed. Accordingly, a part of the outer peripheral surface of the convex curved shape of the metal bushes 7 to 9 (the back surface portion of the high surface pressure generating portions 61 to 63) is cut out (by plane cutting), and the center axis of the metal bushes 7 to 9 is A planar bottom surface extending in a direction perpendicular to the vertical surface is formed.
Each convex curved surface 67 of the metal bushes 7 to 9 is the maximum outer diameter portion of the metal bushes 7 to 9 and is a press-fit surface that is press-fitted to the housing hole wall surface of the cam ring 11 and the housing hole wall surfaces of the housings 12 and 13. It is.

[Operation of Example 1]
Next, the operation of the high-pressure fuel pump (supply pump) of this embodiment will be briefly described with reference to FIGS.

When the camshaft of the supply pump is driven by a belt driven by the crankshaft of the engine and rotates, the plurality of plungers 1 to 3 reciprocally slide in the cylinder holes 27 to 29 of the cylinder bodies 17 to 19.
For example, when the first plunger 1 located at the top dead center is lowered, the fuel pressure in the fuel pressurizing chamber 31 is lowered. When the fuel pressure in the fuel supply passage (fuel hole or the like) becomes larger than the resultant force of the urging force of the return spring of the fuel intake valve 34 and the fuel pressure in the fuel pressurizing chamber 31, The valve opens. That is, the valve is detached from the valve seat surface of the valve body and the fuel supply passage is opened. Thereby, the fuel delivered from the feed pump is sucked into the fuel pressurizing chamber 31 from the electromagnetic fuel metering valve through the fuel supply passage.

When the plunger 1 starts to rise again after reaching the bottom dead center, the fuel pressure in the fuel pressurizing chamber 31 is increased, and the fuel pressure in the fuel supply passage (fuel hole or the like) is changed to the fuel intake valve. When it becomes lower than the resultant force of the urging force of the return spring 34 and the fuel pressure in the fuel pressurizing chamber 31, the valve of the fuel intake valve 34 is closed. That is, the valve is seated on the valve seat surface of the valve body and the fuel supply passage is closed, and at the same time, the fuel pressure in the fuel pressurizing chamber 31 further increases. At this time, the fuel is pressurized and compressed to a high pressure in the fuel pressurizing chamber 31.
When the fuel pressure in the fuel pressurizing chamber 31 rises above the opening pressure of the discharge valve, the valve of the fuel discharge valve 37 opens, and the fuel hole → discharge port and high-pressure pump piping from the fuel pressurizing chamber 31. High-pressure fuel is fed into the common rail through (fuel piping).

The remaining second and third plungers 2 and 3 also slide in a reciprocating manner between the top dead center and the bottom dead center in the same manner as the plunger 1 described above, so that the remaining fuel pressure chambers 32 and 33 The fuel is pumped and supplied into the common rail through the fuel discharge valves 38 and 39 and the high-pressure pump pipe (fuel pipe). Thus, the supply pump is configured such that the suction stroke and the discharge stroke are performed for three cycles per one rotation of the camshaft.
The high-pressure fuel accumulated in the common rail can be supplied to the combustion chamber of each cylinder of the engine at a predetermined timing by driving an actuator such as an electromagnetic valve of the injector at an arbitrary injection timing. .

[Features of Example 1]
Next, features of the high-pressure fuel pump (supply pump) of this embodiment will be described with reference to FIGS.

First, as shown in FIG. 3A, a radial load is applied from the cam 4 to the metal bush 7 that surrounds the cam 4 of the camshaft in the circumferential direction, as shown in FIG. In response to this, a high surface pressure generating portion 61 that generates excessive surface pressure (high surface pressure F) is formed.
On the other hand, the metal bushes 8 and 9 that surround the circumferences of the journals 5 and 6 of the camshaft in the circumferential direction, as shown in FIG. High surface pressure generating portions 62 and 63 are formed in which an excessive surface pressure (high surface pressure F) is generated by receiving a radial load from 4.
In the high-pressure fuel pump of the present embodiment, the plurality of plungers 1 to 3 are installed at predetermined angular intervals (for example, 120 ° equal intervals) in the circumferential direction of the cam chamber 20, so that a plurality of high surface pressures are generated. The parts 61 to 63 are also formed at predetermined angular intervals (for example, 120 ° equal intervals) in the inner circumferential direction of the metal bushes 7 to 9.

Here, the radial load received by the high surface pressure generators 61 to 63 is that of the metal bushes 7 to 9 depending on the driving force or reaction force of the plungers 1 to 3 and the pressing load (concentrated load) of the coil springs 14 to 16. This is a load formed by a load of a certain value or more acting on each of the high surface pressure generators 61 to 63 (load accompanying the pressurization and pressure feeding of the plunger 1).
Further, the direction in which the high surface pressure F is generated in the high surface pressure generating portions 62 and 63 of the metal bushes 8 and 9 is 180 relative to the direction in which the high surface pressure generating portion 61 of the metal bush 7 is generated. ° The direction is reversed.

In the conventional high-pressure fuel pump, for the purpose of suppressing seizure of the sliding portion between the cam 4 of the camshaft and the metal bush 7, the gap between the sliding surface of the cam 4 and the sliding surface of the metal bush 7 is used. However, there is a problem that the oil film is easily cut by the high surface pressure F received by the high surface pressure generators 61 to 63.
In the conventional high-pressure fuel pump, the cam ring 11 having bearing holders that surround the metal bushes 7 to 9 in the circumferential direction and the bearing holders of the housings 12 and 13 are formed of a rigid body such as a metal block. As a result, even if the rear side of the high surface pressure generating portions 61 to 63 of the metal bushes 7 to 9 receives a radial load from the cam 4 or each of the journals 5 and 6 and tries to bend and deform in the direction in which the high surface pressure F is generated. Since the deformation on the back side of the high surface pressure generating parts 61 to 63 is restricted by the bearing holder, the cams 4 and the journals 5 and 6 are worn so that the high surface pressure generating parts 61 to 63 are scooped.
As a result, there is a problem that the wear amount of the metal bushes 7 to 9 increases, for example, in the initial conforming process.

Therefore, in the high-pressure fuel pump of this embodiment, the amount of wear of the metal bushes 7 to 9 is reduced, the adhesion wear of the metal bushes 7 to 9 is reduced, and the cam 4, the journals 5 and 6, and the metal bushes 7 to 9 are reduced. For the purpose of improving the seizure resistance of the sliding part with the cam 9, the radial load from the cam 4, the journals 5, 6 between the cam 4, the journals 5, 6 and the metal bushes 7-9 of the camshaft. Accordingly, a deformation relief portion is provided for allowing bending deformation on the back side of each of the high surface pressure generating portions 61 to 63 of the metal bushes 7 to 9 in the direction in which the high surface pressure F is generated.
The deformation relief portion is provided by forming gaps S1 to S3 between the cam ring 11, the housing hole wall surfaces of the housings 12 and 13, and the metal bushes 7 to 9. Thereby, since it becomes possible to ensure the deformation allowance of the metal bushes 7-9, it becomes easy to deform | transform the metal bushes 7-9. That is, the metal bushes 7 to 9 can be easily deformed in a direction in which a high surface pressure F is generated by receiving a radial load from the cam 4 of the camshaft and the journals 5 and 6.

As a result, the metal bushes 7 to 9 receive a radial load from the cam 4 and the journals 5 and 6 of the camshaft, and the surface pressure between the cam 4 and the journals 5 and 6 and the metal bushes 7 to 9 is localized. However, the deformation of the metal bushes 7-9 makes it possible to increase the pressure receiving area at each of the high surface pressure generating portions 61-63 of the metal bushes 7-9, so that the camshaft cam 4, each journal 5 and 6 and the surface pressure between the high surface pressure generating portions 61 to 63 of the metal bushes 7 to 9 can be reduced.
As a result, fuel as lubricating oil can easily enter the sliding portions between the cam 4 of the cam shaft, the journals 5 and 6, and the high surface pressure generating portions 61 to 63 of the metal bushes 7 to 9. Since an oil film is efficiently formed on the sliding portions between the cam 4 and the journals 5 and 6 and the high surface pressure generating portions 61 to 63 of the metal bushes 7 to 9, the cam 4 of the camshaft and the journals 5 and 6. And lubrication of the sliding portion between the metal bushes 7-9.

  As a result, the wear resistance and seizure resistance of the sliding portion between the cam shaft cam 4, each journal 5, 6 and the metal bushes 7-9 can be improved, so that the durability of the high-pressure fuel pump can be improved. . Further, it is possible to prevent wear and seizure of the sliding portions between the cam 4 of the camshaft, the journals 5 and 6, and the metal bushes 7-9. Moreover, the wear amount of each high surface pressure generating part 61-63 of the metal bushes 7-9 can be reduced significantly. Moreover, the adhesive wear of each high surface pressure generating part 61-63 of the metal bushes 7-9 can be reduced. Moreover, since the seizure resistance of the sliding portion between the cam 4 of the camshaft, the journals 5 and 6, and the metal bushes 7 to 9 can be improved, the durability of the high-pressure fuel pump can be improved.

Next, modifications of the metal bushes 7 to 9 of the present embodiment will be briefly described with reference to FIGS.
A plurality of gaps S1 to S1 which are deformation escape portions for allowing deformation of the metal bushes 7 to 9 in a direction in which a high surface pressure F is generated by receiving a radial load from the cam 4 of the camshaft and the journals 5 and 6. S3 is provided by forming the deformation relief grooves 64 to 66 on the back surfaces of the high surface pressure generating portions 61 to 63 of the metal bushes 7 to 9 in the same manner as the example shown in FIG.

Here, FIG. 4 is a view showing Modification 1 of the metal bushes 7 to 9.
First, in each of the deformation relief grooves 64 to 66 of the metal bushes 7 to 9 shown in FIG. 4A, a flat planar bottom surface (plane FA) is provided. Further, the metal bushes 7 to 9 are provided with intersecting ridgelines EL1 and EL2 between the bottom surfaces of the deformation escape grooves 64 to 66 and the outer peripheral surfaces (convex curved surfaces 67 to 69) of the metal bushes 7 to 9, respectively. The bottom surfaces of the deformation escape grooves 64 to 66 are formed between the two intersecting ridgelines EL1 and EL2. And the bottom face of the deformation | transformation escape grooves 64-66 cuts out a part (back surface part of the high surface pressure generation | occurrence | production parts 61-63) of the outer peripheral surface of the convex-curved shape of the metal bushes 7-9. It is formed.

Next, in each of the deformation relief grooves 64 to 66 of the metal bushes 7 to 9 shown in FIG. 4B, a convex curved bottom surface (curved surface CA) is formed. Further, the metal bushes 7 to 9 are provided with intersecting ridgelines EL1 and EL2 between the bottom surfaces of the deformation escape grooves 64 to 66 and the outer peripheral surfaces of the metal bushes 7 to 9, respectively. The bottom surfaces of the deformation escape grooves 64 to 66 are formed between the two intersecting ridgelines EL1 and EL2. Then, a convex curved surface having a radius of curvature larger than the radius of curvature of the convex curved surface of the metal bushes 7 to 9, that is, a gently convex curved curved bottom surface is formed on a part of the outer peripheral surface of the convex curved surface shape of the metal bushes 7 to 9. You may make it form.
As a result, the contact surface pressure between the cam 4 of the camshaft, the journals 5 and 6 and the metal bushes 7 to 9 is uniform as compared with the case where the bottom surfaces of the deformation escape grooves 64 to 66 are formed only by the plane FA. It is possible to escape.

Next, in each of the deformation relief grooves 64 to 66 of the metal bushes 7 to 9 shown in FIG. 4C, a convex curved bottom surface (curved surface CA) is formed. Further, the metal bushes 7 to 9 are formed by rounding the intersecting ridge lines between the bottom surfaces of the deformation escape grooves 64 to 66 and the outer peripheral surfaces (convex curved surfaces 67 to 69) of the metal bushes 7 to 9. Mild convex curved surfaces CA1 and CA2 are formed between the bottom surface of 66 and the outer peripheral surfaces of the metal bushes 7-9.
Accordingly, both the flat and convex curved surfaces are provided on the bottom surfaces of the deformation escape grooves 64 to 66, so that the metal bushes 7 to 6 are compared with those in which the bottom surfaces of the deformation escape grooves 64 to 66 are formed only by the curved surface CA. Since the deformation allowance of 9 (the cross-sectional area of the gaps S1 to S3) can be increased, it is possible to cope with higher surface pressure F.

Here, FIG. 5 is a view showing a second modification of the metal bushes 7 to 9.
In the deformation relief grooves 64 to 66 of the metal bushes 7 to 9 shown in FIG. 5, a flat bottom surface (FA) extending straight in the central axis direction of the metal bushes 7 to 9 (the rotation axis direction of the camshaft). Is formed. Thus, the plurality of gaps S1 to S3 which are deformation escape portions for allowing the deformation of the metal bushes 7 to 9 are uniform throughout the central axis direction of the metal bushes 7 to 9 (the rotational axis direction of the camshaft). It has various cross-sectional areas.
In addition, the metal bushes 7 to 9 are similar to the metal bushes 7 to 9 shown in FIG. 4 in that the bottom surfaces (plane FA) of the deformation escape grooves 64 to 66 and the outer peripheral surfaces (convex curved surfaces 67 to 67) of the metal bushes 7 to 9. 69) and intersecting ridgelines EL1 and EL2, respectively.

Here, FIG. 6 is a view showing a third modification of the metal bushes 8 and 9.
The high surface pressure generating portion 62 of the metal bush 8 shown in FIG. 6 is one end side (side closer to the cam 4 than the center of the axial direction of the metal bush 8, the high pressure fuel pump (camshaft) in FIG. 2. It is set (formed) closer to the rear (Re) side in the rotation axis direction: the left end side in the figure. Further, the high surface pressure generating portion 63 of the metal bush 9 shown in FIG. 6 has one end side (a side closer to the cam 4 than the center in the axial direction of the metal bush 9, a high pressure fuel pump (camshaft in FIG. 2). ) Is set (formed) closer to the front (Fr) side in the rotation axis direction (the left end side in the figure).
As described above, when the metal bushes 8 and 9 are viewed from the side of the high-pressure fuel pump, the deformation relief grooves 65 and 66 are closer to one end side (the left side in the drawing in FIG. 6) than the center of the metal bushes 8 and 9 in the axial direction. It is desirable to set the clearances S1 to S3 which are deformation escape portions only on the back side of the high surface pressure generating portions 62 and 63.

First, the metal bushes 8 and 9 shown in FIG. 6B are the bottom surfaces (plane FA) of the deformation escape grooves 65 and 66 and the outer peripheral surfaces (convex curved surfaces) of the outer peripheral portions (fitting portions 70) of the metal bushes 8 and 9. (Press-fit surface) 68, 69) and a step 71 is formed.
The fitting portion 70 having a convexly curved press-fitting surface is a cylindrical thick portion extending in the circumferential direction of the metal bushes 8 and 9 (when the side having the deformation escape grooves 65 and 66 is a thin portion, A portion that is thicker than the thin-walled portion) and is an annular portion that is press-fitted into the housing hole wall surface of the cam ring 11 and the housing hole wall surfaces of the housings 12 and 13.

The step 71 is provided near the center of the metal bushes 8 and 9 in the axial direction. The step 71 is provided at an edge (cross ridge line ELa) on one end side in the rotation axis direction of the fitting portion 70. Thereby, the deformation escape grooves 65 and 66 are formed on one end side in the axial direction of the metal bush 8 with respect to the step 71 of the metal bushes 8 and 9. The gaps S1 to S3 are provided only on the back side of the high surface pressure generators 62 and 63.
In this manner, the metal bushes 8 and 9 are close to one end side in the axial direction, that is, only on the back side of the high surface pressure generating portions 62 and 63 that generate a high surface pressure F by receiving a radial load from the journals 5 and 6 of the camshaft. Since the deformation relief portions (gap S1 to S3) can be provided, the tension (holding force) against the press-fitting surfaces (convex curved surfaces 68 and 69) of the fitting portions 70 of the metal bushes 8 and 9 on the housing hole wall surfaces of the housings 12 and 13 can be provided. Power) can be maintained.

Next, in the metal bushes 8 and 9 shown in FIG. 6C, the bottom surfaces of the deformation escape grooves 65 and 66 are from one end in the axial direction of the metal bushes 8 and 9 (the same direction as the rotation axis direction of the camshaft). It inclines with respect to the axial direction of the metal bushes 8 and 9 so that it may become an upward slope toward the center vicinity (it becomes shallow gradually). The bottom surfaces of the deformation escape grooves 65 and 66 are flat inclined surfaces 73 as shown in FIG.
In this case, similar to the metal bushes 8 and 9 shown in FIG. 6B, the metal bushes 8 and 9 are close to one end side in the axial direction, that is, they receive a radial load from the journals 5 and 6 of the camshaft and receive a high surface pressure. Since the deformation relief portions (gap S1 to S3) can be set only on the back side of the high surface pressure generating portions 62 and 63 where F is generated, the fitting portions 70 of the metal bushes 8 and 9 on the housing hole wall surfaces of the housings 12 and 13 are provided. The pressing force (holding force) against the press-fitting surfaces (convex curved surfaces 68 and 69) can be maintained.

The inclination angle of the bottom surfaces (inclined surfaces 73) of the deformation escape grooves 65 and 66 may correspond to the surface pressure distribution of the high surface pressure generating portions 62 and 63 of the metal bushes 8 and 9. For example, the cross-sectional area of the gaps S1 to S3 formed on the back side of the portion with high surface pressure in the high surface pressure generating portions 62 and 63 is the portion of the high surface pressure generating portions 62 and 63 where the surface pressure is low. The inclination angle of the inclined surface 73 of the deformation relief grooves 65 and 66 corresponding to the surface pressure distribution is set so as to be larger than the cross-sectional area of the gaps S1 to S3 formed on the back side.
In this case, it is possible to secure a deformation allowance of the metal bushes 8 and 9 according to the surface pressure distribution that changes corresponding to the position in the axial direction of the high surface pressure generating portions 62 and 63 of the metal bushes 8 and 9.

Next, in the metal bushes 8 and 9 shown in FIG. 6D, the bottom surfaces of the deformation escape grooves 65 and 66 are from one end in the axial direction of the metal bushes 8 and 9 (the same direction as the rotation axis direction of the camshaft). It inclines with respect to the axial direction of the metal bushes 8 and 9 so that it may become an upward slope toward the center vicinity (it becomes shallow gradually). The bottom surfaces of the deformation escape grooves 65 and 66 are curved convex curved surfaces 75 as shown in FIG. Alternatively, the bottom surfaces of the deformation escape grooves 65 and 66 may be concave curved surfaces.
In this case, as in the case of the metal bushes 8 and 9 shown in FIGS. 6B and 6C, the radial load is received from the journals 5 and 6 of the camshaft near the one end side of the metal bushes 8 and 9 in the axial direction. Since the deformation relief portions (gap S1 to S3) can be set only on the back side of the high surface pressure generating portions 62 and 63 where the high surface pressure F is generated, the metal bushes 8 and 9 on the housing hole wall surfaces of the housings 12 and 13 can be set. Tension force (holding force) against the press-fitting surface (convex curved surfaces 67 to 69) can be maintained.
Further, since stress concentration on the end face edge (cross ridge line EL3) on one end side in the axial direction of the metal bushes 8 and 9 can be alleviated, the wear of the sliding portion between the journals 5 and 6 of the camshaft and the metal bushes 8 and 9 can be reduced. Burn-in can be prevented.

Note that the inclination angle of the bottom surfaces (convex curved surface 75) of the deformation relief grooves 65, 66 may correspond to the surface pressure distribution of the high surface pressure generating portions 62, 63 of the metal bushes 8, 9. For example, the cross-sectional area of the gaps S1 to S3 formed on the back side of the portion with high surface pressure in the high surface pressure generating portions 62 and 63 is the portion of the high surface pressure generating portions 62 and 63 where the surface pressure is low. The inclination angle of the convex curved surface 75 of the deformation relief grooves 65 and 66 corresponding to the surface pressure distribution is set so as to be larger than the cross-sectional area of the gaps S1 to S3 formed on the back side.
In this case, as with the metal bushes 8 and 9 shown in FIG. 6C, the surface pressure distribution varies according to the axial position of the high surface pressure generating portions 62 and 63 of the metal bushes 8 and 9. The deformation allowance of the metal bushes 8 and 9 can be secured.
Here, the mode (modified example) shown in FIG. 6 may be applied to the metal bush 7. In this case, the deformation escape groove 64 is set near the center of the metal bush 7.

Here, FIG. 7 is a view showing a fourth modification of the metal bushes 8 and 9.
In the case of the metal bush 8, the formation position of the high surface pressure generating portion 62, the deformation escape groove 65 and the gaps S <b> 1 to S <b> 3 is set to one end side (the side closer to the cam 4 than the center of the metal bush 8 in the axial direction). 2 is set closer to the Re side of the high-pressure fuel pump. In the case of the metal bush 9, the formation position of the high surface pressure generating portion 63, the deformation relief groove 66 and the gaps S <b> 1 to S <b> 3 is set to one end side (the distance from the cam 4 is smaller than the center of the metal bush 9 in the axial direction). It is set closer to the near side (Fr side of the high-pressure fuel pump in FIG. 2).
As described above, the metal bushes 8 and 9 installed between the outer peripheral surfaces of the journals 5 and 6 of the camshaft and the housing hole wall surfaces of the housings 12 and 13 are assembled in the press-fitting direction with respect to the housing hole wall surfaces of the housings 12 and 13. The directions are opposite to each other (the direction opposite to 180 °).
Therefore, in consideration of the direction of one end side (high surface pressure generating portion forming side) of the metal bushes 8 and 9 in the axial direction, it is necessary to press-fit and fix to the housing hole wall surfaces of the housings 12 and 13, and the assembling property is poor. There is a problem that the cost increases.

Therefore, first, a cylindrical fitting portion 70 that is press-fitted and fixed to the wall surface of the housing hole of the housings 12 and 13 is provided at the central portion in the axial direction of the metal bushes 8 and 9 shown in FIG. Yes. The outer peripheral surface of the fitting portion 70 is a press-fitting surface (convex curved surfaces 68 and 69) having a convex curved shape over the entire circumferential direction.
Further, high surface pressure generating portions 62 and 63 and deformation escape grooves 65 and 66 are set (formed) on both ends of the metal bushes 8 and 9 in the axial direction.
Further, the metal bushes 8 and 9 include a step 71 formed between the bottom surface (plane FA) of the deformation escape groove 65 on the left side of the drawing and the outer peripheral surface (press-fit surfaces 68 and 69) of the fitting portion 70, and the right side of the drawing. A step 72 is formed between the bottom surface (plane FA) of the deformation escape groove 66 and the outer peripheral surface (press-fit surface 68, 69) of the fitting portion 70.

The steps 71 and 72 are provided near the center of the metal bushes 8 and 9 in the axial direction. The step 71 is provided at the edges (crossing ridge lines ELa and ELb) on both ends of the fitting portion 70 in the rotation axis direction. Thereby, the deformation | transformation relief grooves 64-66 are formed in the both ends side of the axial direction of the metal bush 8 rather than the level | step differences 71 and 72 of the metal bushes 8 and 9. FIG. And the clearance gaps S1-S3 are provided only in the back side of the high surface pressure generation | occurrence | production parts 62 and 63 of both sides.
As described above, the metal bushes 8 and 9 are close to both ends in the axial direction, that is, on the back side of the high surface pressure generating portions 62 and 63 that generate a high surface pressure F by receiving a radial load from the journals 5 and 6 of the camshaft. Since only the deformation relief portions (gap S1 to S3) can be provided, the pressing force (holding force) against the press-fitting surfaces (convex curved surfaces 68 and 69) of the metal bushes 8 and 9 on the housing hole wall surfaces of the housings 12 and 13 is maintained. can do.
In this case, there is no need to distinguish the direction of the press-fitting direction (assembly direction) of the metal bushes 8 and 9 with respect to the housing hole wall surfaces of the housings 12 and 13 of the high-pressure fuel pump. , 9 can be improved in workability (assembly workability). Thereby, the manufacturing cost of a high-pressure fuel pump can be reduced.

Next, in the metal bushes 8 and 9 shown in FIG. 7C, the bottom surfaces of the deformation escape grooves 65 and 66 on both sides are in the axial direction of the metal bushes 8 and 9 (the same direction as the rotation axis direction of the camshaft). The both ends (one end and the other end) are inclined with respect to the axial direction of the metal bushes 8 and 9 so as to be upwardly inclined toward the center (slightly shallower). The bottom surfaces of the deformation escape grooves 65 and 66 on both sides are flat inclined surfaces 73 and 74 as shown in FIG.
In this case, similar to the metal bushes 8 and 9 shown in FIG. 7B, the metal bushes 8 and 9 are close to both ends in the axial direction, that is, they receive a radial load from the journals 5 and 6 of the camshaft and receive a high surface pressure. Since the deformation relief portions (gap S1 to S3) can be set only on the back side of the high surface pressure generating portions 62 and 63 where F is generated, the fitting portions 70 of the metal bushes 8 and 9 on the housing hole wall surfaces of the housings 12 and 13 are provided. The pressing force (holding force) against the press-fitting surfaces (convex curved surfaces 68 and 69) can be maintained.
Note that the inclination angle of the bottom surfaces (inclined surfaces 73 and 74) of the deformation escape grooves 65 and 66 may correspond to the surface pressure distribution of the high surface pressure generating portions 62 and 63 of the metal bushes 8 and 9. In this case, it is possible to secure a deformation allowance of the metal bushes 8 and 9 according to the surface pressure distribution that changes corresponding to the position in the axial direction of the high surface pressure generating portions 62 and 63 of the metal bushes 8 and 9.

Next, in the metal bushes 8 and 9 shown in FIG. 7D, the bottom surfaces of the deformation escape grooves 65 and 66 on both sides are in the axial direction of the metal bushes 8 and 9 (the same direction as the rotation axis direction of the camshaft). It inclines with respect to the axial direction of the metal bushes 8 and 9 so that it may become an up-slope toward the center vicinity from both ends (it becomes shallow gradually). The bottom surfaces of the deformation escape grooves 65 and 66 are curved convex curved surfaces 75 and 76 as shown in FIG. Alternatively, the bottom surfaces of the deformation escape grooves 65 and 66 may be concave curved surfaces.
In this case, as in the case of the metal bushes 8 and 9 shown in FIGS. 7B and 7C, the metal bushes 8 and 9 receive radial loads from the axial ends of the metal bushes 8 and 9, that is, from the journals 5 and 6 of the camshaft. Since the deformation relief portions (gap S1 to S3) can be set only on the back side of the high surface pressure generating portions 62 and 63 where high surface pressure is generated, the metal bushes 8 and 9 are press-fitted into the housing hole wall surfaces of the housings 12 and 13. The tightening force (holding force) for the surfaces (convex curved surfaces 68 and 69) can be maintained.

In addition, since stress concentration on the end face edge (cross ridge line EL3, EL4) on one end side in the axial direction of the metal bushes 8, 9 can be reduced, the sliding portion between the journals 5, 6 of the camshaft and the metal bushes 8, 9 can be reduced. Wear and seizure can be prevented.
The inclination angle of the bottom surfaces (convex curved surfaces 75, 76) of the deformation escape grooves 65, 66 may correspond to the surface pressure distribution of the high surface pressure generating portions 62, 63 of the metal bushes 8, 9. In this case, similarly to the metal bushes 8 and 9 shown in FIG. 7C, the surface pressure distribution varies according to the axial position of the high surface pressure generators 62 and 63 of the metal bushes 8 and 9. The deformation allowance of the metal bushes 8 and 9 can be secured.

  FIG. 8 shows a second embodiment of the present invention, FIG. 8 (a) is a diagram showing a cam bearing structure of a camshaft, and FIG. 8 (b) is a diagram showing a journal bearing structure of a camshaft. is there.

As in the first embodiment, the high-pressure fuel pump according to the present embodiment is a cam in which a pump element including a plurality (three) of plungers 1 to 3 and cylinder bodies 17 to 19 is formed by housings 12 and 13. It is installed in the circumferential direction of the chamber 20 at predetermined angular intervals (for example, 120 ° equal intervals).
The cam shaft rotatably supported by the housings 12 and 13 is integrally provided with a cam 4 for reciprocating the plungers 1 to 3 and two journals 5 and 6 installed on both sides of the cam 4 in the rotation axis direction. Is provided.

A cylindrical metal bush 7 is installed between the cam 4 of the cam shaft and the cam ring 11 so as to surround the cam 4.
Cylindrical metal bushes 8 and 9 are installed between the journals 5 and 6 of the camshaft and the housings 12 and 13 so as to surround the journals 5 and 6. For the purpose of suppressing seizure of the sliding portion between the cam 4 of the camshaft and the metal bush 7 and suppressing seizure of the sliding portion between the journals 5 and 6 and the metal bushes 8 and 9, for example, Fuel is supplied as lubricating oil from the cam chamber 20 or the feed pump.

Here, the metal bushes 7 to 9 of the present embodiment are similar to the first embodiment in that the camshaft cam 4 and the journals 5, 6 are in contact with the camshaft cam 4 and the journals 5, 6. Are provided with high surface pressure generating portions 61 to 63 that receive a radial load from the surface and generate excessive surface pressure (high surface pressure F).
And between the cam ring 11 and the housings 12 and 13 and the metal bushes 7 to 9, a radial load is received from the cam 4 of the camshaft and the journals 5 and 6 in the direction in which the high surface pressure F is generated. A deformation relief portion for allowing deformation of the metal bushes 7 to 9 is set.
The deformation relief portions of the metal bushes 7 to 9 are provided by forming a plurality (three) of gaps S1 to S3 between the cam ring 11, the housings 12 and 13, and the metal bushes 7 to 9.

The plurality of gaps S1 to S3 are the cam ring 11 in the direction in which a high surface pressure F is generated by receiving a radial load from the cam 4 of the camshaft, the journals 5 and 6, and the wall surface of the housing hole of the housings 12 and 13, that is, the high surface pressure. It is provided by denting the back surface of the generators 61 to 63 to the opposite side (outside in the radial direction of the cam shaft) with respect to the cam shaft side. Specifically, a plurality of deformation relief grooves (recesses) 64 to 66 are formed on the opposing surfaces (the wall surfaces of the housing holes of the cam ring 11 and the housings 12 and 13) that face the back surfaces of the high surface pressure generating units 61 to 63. Gaps S1 to S3 are provided.
As described above, in the high-pressure fuel pump of this embodiment, the gaps S1 to S3 for allowing deformation of the metal bushes 7 to 9 are provided between the cam ring 11, the housings 12 and 13, and the metal bushes 7 to 9. Since it is provided, it is possible to maintain the pressing force (holding force) against the press-fitting surfaces (convex curved surfaces 67 to 69) of the metal bushes 8 and 9 on the housing hole wall surfaces of the housings 12 and 13, and the same effect as in the first embodiment. Can be achieved.

  FIG. 9 shows a third embodiment of the present invention, FIG. 9 (a) is a diagram showing a cam bearing structure of a camshaft, and FIG. 9 (b) is a diagram showing a journal bearing structure of a camshaft. is there.

Similarly to the first and second embodiments, the metal bushes 7 to 9 of the present embodiment are arranged on the sliding portions of the camshaft cam 4 and the respective journals 5 and 6 from the camshaft cam 4 and the respective journals 5 and 6. High surface pressure generators 61 to 63 that generate excessive surface pressure (high surface pressure F) in response to a radial load are provided.
And between the cam ring 11 and the housings 12 and 13 and the metal bushes 7 to 9, a radial load is received from the cam 4 of the camshaft and the journals 5 and 6 in the direction in which the high surface pressure F is generated. A deformation relief portion for allowing deformation of the metal bushes 7 to 9 is set.

The deformation relief portions of the metal bushes 7 to 9 are provided by forming a plurality (three) of gaps S1 to S3 between the cam ring 11, the housings 12 and 13, and the metal bushes 7 to 9.
The plurality of gaps S1 to S3 are formed by the cam ring 11 and the housings 12 and 13 and the metal bushes 7 to 9 in the direction in which the radial load is not generated from the cam 4 of the camshaft and the journals 5 and 6 and the high surface pressure F is not generated. It is provided only by sandwiching a restricting part 81 having an arcuate cross section for restricting deformation of the metal bushes 7 to 9 to the cam ring side and the housing side. The restriction parts 81 to 83 are separate parts separately provided for the metal bushes 7 to 9 and the cam ring 11 and the housings 12 and 13, and are rigid bodies made of a material harder than at least the metal bushes 7 to 9 ( It is desirable to use (metal products).

  As described above, in the high-pressure fuel pump according to the present embodiment, a high surface pressure F is received by receiving a radial load from the cam 4 of the camshaft and the journals 5 and 6 on the back side of the high surface pressure generators 61 to 63. Since the gaps S1 to S3 for allowing deformation of the metal bushes 7 to 9 are provided only in the direction in which the metal bushes 7 to 9 are generated, the press-fitting surfaces (convex curved surfaces 68) of the metal bushes 8 and 9 in the housing hole wall surfaces of the housings 12 and 13 are provided. 69), and the same effect as that of the first embodiment can be achieved.

  10 to 12 show a fourth embodiment of the present invention. FIGS. 10 and 11 show a camshaft bearing structure of a high-pressure fuel pump. FIG. 12 (a) shows a camshaft cam bearing structure. FIG. 12B is a view showing a journal bearing structure of a camshaft.

  The high-pressure fuel pump of this embodiment includes a plurality of (two) plungers 1 and 2 that reciprocate in the axial direction and pressurize and pressure-feed fuel, and a camshaft that drives these plungers 1 and 2 in the reciprocating direction. And cylindrical metal bushes 7 to 9 and oil sleeve 10 installed so as to surround the circumference of the cam shaft in the circumferential direction, and bearing sleeves surrounding the circumference of the metal bushes 7 to 9 in the circumferential direction, respectively. A cam ring 11, housings 12 and 13, coil springs 14 to 16 for generating loads (pressing loads) for pressing the plungers 1 and 2 against respective seating surfaces of the cam ring 11, and the plungers 1 and 2 in the reciprocating direction thereof. From cylinder bodies 17 and 18 having cylindrical cylinders that are slidably supported on the cylinder and a feed pump as a lubricating oil supply means. Fuel as lubricating oil and a cam chamber 20 which is supplied via the oil supply passage.

Unlike the first to third embodiments, the high-pressure fuel pump has a cam element 20 in which a pump element including a plurality (two) of plungers 1 and 2 and cylinder bodies 17 and 18 is formed by the housings 12 and 13 They are installed in the circumferential direction at predetermined angular intervals (for example, 180 ° equal intervals).
A cam shaft rotatably supported by the housings 12 and 13 is integrally provided with a cam 4 for reciprocating the plungers 1 and 2 and two journals 5 and 6 installed on both sides of the rotation axis direction of the cam 4. Is provided.
A cylindrical metal bush 7 is installed between the cam 4 of the cam shaft and the cam ring 11 so as to surround the cam 4.

  Here, the cam ring 11 has a quadrangular prism shape. On the outer peripheral surface of the cam ring 11, planar seat surfaces 51, 52 that receive the driving reaction force (fuel pressure load) from the plungers 1, 2 and the pressing load from the coil springs 14, 15 are provided. Cylindrical metal bushes 8 and 9 are installed between the journals 5 and 6 of the camshaft and the housings 12 and 13 so as to surround the journals 5 and 6. For the purpose of suppressing seizure of the sliding portion between the cam 4 of the camshaft and the metal bush 7 and suppressing seizure of the sliding portion between the journals 5 and 6 and the metal bushes 8 and 9, for example, Fuel is supplied as lubricating oil from the cam chamber 20 or the feed pump.

Here, the metal bushes 7 to 9 of this embodiment receive a radial load from the camshaft cam 4 and the journals 5 and 6 at the sliding portions with the camshaft cam 4 and the journals 5 and 6. High surface pressure generators 61 to 63 that generate the surface pressure F are provided.
In the high-pressure fuel pump of this embodiment, the plurality of plungers 1 and 2 are installed in the circumferential direction of the cam chamber 20 at a predetermined angular interval (for example, equal to 180 °), so that a plurality of high surface pressures are generated. The parts 61 to 63 are also formed at predetermined angular intervals (for example, 180 ° equal intervals) in the inner circumferential direction of the metal bushes 7 to 9.
Between the cam ring 11 and the housings 12 and 13 and the metal bushes 7 to 9, the metal bushes in the direction in which a high surface pressure F is generated by receiving a radial load from the cam 4 and the journals 5 and 6 of the camshaft. A deformation escape portion for allowing deformation of 7 to 9 is set. The deformation relief portions of the metal bushes 7-9 are provided by forming a plurality (two) of gaps S1, S2 between the cam ring 11, the housings 12, 13 and the metal bushes 7-9.

The plurality of gaps S1 and S2 are the outer peripheral surfaces of the metal bushes 7 to 9 in the direction in which the high surface pressure F is generated by receiving a radial load from the cam 4 of the camshaft and the journals 5 and 6, that is, the high surface pressure generator 61. ˜63 are provided by denting the back surface of the camshaft side. Specifically, a plurality of gaps S <b> 1 and S <b> 2 are provided by forming deformation relief grooves (recesses) 64 to 66 on the back surface of the high surface pressure generating parts 61 to 63.
As described above, in the high-pressure fuel pump of this embodiment, the gaps S1 and S2 for allowing deformation of the metal bushes 7 to 9 are provided between the cam ring 11, the housings 12 and 13, and the metal bushes 7 to 9. Since it is provided, it is possible to maintain the pressing force (holding force) against the press-fitting surfaces (convex curved surfaces 68, 69) of the metal bushes 8, 9 on the housing hole wall surfaces of the housings 12, 13, and the same as in the first to third embodiments. The effect can be achieved.

  FIG. 13 shows a fifth embodiment of the present invention, FIG. 13 (a) is a diagram showing the cam bearing structure of the camshaft, and FIG. 13 (b) is a diagram showing the journal bearing structure of the camshaft. is there.

As in the first embodiment, the metal bushes 7 to 9 of the present embodiment have a radial load from the camshaft cam 4 and the journals 5 and 6 on the sliding portions of the camshaft cam 4 and the journals 5 and 6. In response, high surface pressure generating portions 61 to 63 that generate high surface pressure F are provided.
And between the cam ring 11 and the housings 12 and 13 and the metal bushes 7 to 9, a radial load is received from the cam 4 of the camshaft and the journals 5 and 6 in the direction in which the high surface pressure F is generated. A deformation relief portion for allowing deformation of the metal bushes 7 to 9 is set.
The deformation relief portions of the metal bushes 7-9 are provided by forming a plurality (two) of gaps S1, S2 between the cam ring 11, the housings 12, 13 and the metal bushes 7-9.

The plurality of gaps S1 and S2 are the cam ring 11 in the direction in which the radial load is generated from the cam 4 of the camshaft and the journals 5 and 6, and the wall surface of the housing hole of the housings 12 and 13, that is, the high surface pressure. It is provided by denting the back surface of the generators 61 to 63 to the opposite side (outside in the radial direction of the cam shaft) with respect to the cam shaft side. Specifically, a plurality of deformation relief grooves (recesses) 64 to 66 are formed on the opposing surfaces (the wall surfaces of the housing holes of the cam ring 11 and the housings 12 and 13) that face the back surfaces of the high surface pressure generating units 61 to 63. Gaps S1 and S2 are provided.
As described above, in the high-pressure fuel pump of this embodiment, the same effect as that of Embodiment 4 can be achieved.

  14A and 14B show a sixth embodiment of the present invention. FIG. 14A shows a cam bearing structure of a camshaft, and FIG. 14B shows a journal bearing structure of a camshaft. is there.

Similarly to the first and second embodiments, the metal bushes 7 to 9 of the present embodiment are arranged on the sliding portions of the camshaft cam 4 and the respective journals 5 and 6 from the camshaft cam 4 and the respective journals 5 and 6. High surface pressure generating portions 61 to 63 that generate a high surface pressure F in response to a radial load are provided.
And between the cam ring 11 and the housings 12 and 13 and the metal bushes 7 to 9, a radial load is received from the cam 4 of the camshaft and the journals 5 and 6 in the direction in which the high surface pressure F is generated. A deformation relief portion for allowing deformation of the metal bushes 7 to 9 is set.

The deformation relief portions of the metal bushes 7-9 are provided by forming a plurality (three) of gaps S1, S2 between the cam ring 11, the housings 12, 13 and the metal bushes 7-9.
The plurality of gaps S1 and S2 are formed by the cam ring 11 and the housings 12 and 13 and the metal bushes 7 to 9 in the direction in which no radial load is generated from the cam 4 of the camshaft 4 and the journals 5 and 6 and high surface pressure F is not generated. It is provided only by sandwiching restriction parts 81 to 83 having a circular arc cross section for restricting deformation of the metal bushes 7 to 9 to the cam ring side and the housing side. The restriction parts 81 to 83 are separate parts separately provided for the metal bushes 7 to 9 and the cam ring 11 and the housings 12 and 13, and are rigid bodies made of a material harder than at least the metal bushes 7 to 9 ( It is desirable to use (metal products).
As described above, in the high-pressure fuel pump of this embodiment, the same effects as those of Embodiments 4 and 5 can be achieved.

[Modification]
In this embodiment, a diesel engine having a plurality of cylinders is employed as the internal combustion engine (engine), but a gasoline engine having a plurality of cylinders may be employed as the internal combustion engine (engine).
In this embodiment, a common rail type fuel injection system of two injections and one pressure feed type is adopted, but a common rail type fuel injection system of one injection and one pressure feed type may be adopted. Further, the number of pump elements may be one or four in addition to two or three.

In this embodiment, a camshaft that is rotationally driven by an internal combustion engine (engine) is employed, but a camshaft that is rotationally driven by another driving device (for example, an electric actuator having a motor) may be employed. .
Further, the high-pressure fuel pump of the present invention may be applied to a fuel supply device in which a feed pump and a high-pressure fuel pump are separated. For example, the feed pump may be rotationally driven by an electric actuator, and the high-pressure fuel pump may be rotationally driven by an internal combustion engine. The reverse is also possible.

In this embodiment, a cam 4 having a circular cross section is integrally provided on the camshaft, a cam ring 11 is mounted on the outer periphery of the cam 4, and the tappets 44 to 46 of the plungers 1 to 3 are attached to the outer peripheral surface of the cam ring 11. A high-pressure fuel pump having a cam mechanism provided with planar seating surfaces 51 to 53 for receiving a load is employed. However, a cam having a plurality of cam peaks is integrally provided on the cam shaft, and the cam peaks are slid. You may employ | adopt the high pressure fuel pump provided with the cam mechanism which reciprocates a tappet and a plunger via the moving roller.
You may make it provide deformation escape parts, such as clearance gaps S1-S3, between at least 1 metal bush (bearing member) among several metal bushes 7-9, and a block.

1 Plunger (piston)
2 Plunger (piston)
3 Plunger (piston)
4 Camshaft cam 5 Camshaft journal 6 Camshaft journal 7 Metal bush (bearing member)
8 Metal bush (bearing member)
9 Metal bush (bearing member)
11 Cam ring (block)
12 Housing (block, bearing cover)
13 Housing (block, housing body)
14 Coil spring 15 Coil spring 16 Coil spring 17 Cylinder body 18 Cylinder body 19 Cylinder body 20 Cam chamber 61 High surface pressure generator 62 High surface pressure generator 63 High surface pressure generator 64 Deformation relief groove (deformation relief portion, recess)
65 Deformation relief groove (deformation relief part, recess)
66 Deformation relief groove (deformation relief part, recess)
81 Restriction part 82 Restriction part 83 Restriction part S1 Crevice (deformation relief part)
S2 Clearance (deformation relief)
S3 Clearance (deformation relief)

Claims (18)

(A) pistons (1-3) that reciprocate in the cylinder hole and pressurize and feed fuel;
(B) camshafts (4-6) for driving the pistons (1-3) in the moving direction;
(C) a block (11-13) having an accommodation hole for accommodating the camshaft (4-6) so as to be movable in the rotation direction;
(D) a cylindrical bearing member (7-9) fixed to the housing hole wall surface of the block (11-13) and supporting the camshaft (4-6) slidably in the rotational direction;
(E) It is provided between the block (11-13) and the bearing member (7-9), and receives a load from the camshaft (4-6) to generate a high surface pressure. A deformation relief portion for allowing deformation of the bearing member (7-9) ,
The deformation relief portion is
A high-pressure fuel pump provided by forming gaps (S1 to S3) between the blocks (11 to 13) and the bearing members (7 to 9) . The high-pressure fuel pump according to claim 1,
The gaps (S1 to S3) are
The high pressure is provided by denting the outer surface of the bearing member (7-9) toward the camshaft side in a direction in which a high surface pressure is generated by receiving a load from the camshaft (4-6). Fuel pump. The high-pressure fuel pump according to claim 1 or 2 ,
The gaps (S1 to S3) are
It is provided by forming a deformation relief groove (64-66) on the outer surface of the bearing member (7-9) in a direction in which a high surface pressure is generated by receiving a load from the camshaft (4-6). A high-pressure fuel pump. The high-pressure fuel pump according to claim 3 ,
Two deformation escape grooves (64 to 66) are provided in the circumferential direction of the bearing member (7 to 9), and intersect with the outer surface of the bearing member (7 to 9), and between the two intersecting ridge lines. A high-pressure fuel pump characterized by having a flat bottom surface formed on the surface . The high-pressure fuel pump according to claim 3 or 4 ,
Two deformation escape grooves (64 to 66) are provided in the circumferential direction of the bearing member (7 to 9), and intersect with the outer surface of the bearing member (7 to 9), and between the two intersecting ridge lines. A high-pressure fuel pump characterized by having a curved bottom surface formed on the surface . The high-pressure fuel pump according to any one of claims 3 to 5 ,
The bottom surface of the deformation escape groove (64 to 66)
The bearing member (7-9) is inclined with respect to the axial direction of the bearing member (7-9) so as to be inclined upward from one end in the axial direction to the other end or the center. High pressure fuel pump. The high-pressure fuel pump according to any one of claims 3 to 5 ,
The bottom surface of the deformation escape groove (64 to 66)
The high-pressure fuel is inclined with respect to the axial direction of the bearing members (7-9) so as to be inclined upward from both ends in the axial direction of the bearing members (7-9) toward the center . pump. The high-pressure fuel pump according to claim 1 ,
The gaps (S1 to S3) are
It is provided by denting the housing hole wall surface of the block (11-13) in the direction in which a high surface pressure is generated by receiving a load from the camshaft (4-6) on the opposite side to the camshaft side. A high-pressure fuel pump characterized by that. The high-pressure fuel pump according to claim 1 ,
The gaps (S1 to S3) are
The bearing members (7 to 7) are disposed only between the blocks (11 to 13) and the bearing members (7 to 9) in a direction not receiving a load from the camshafts (4 to 6) and generating no high surface pressure. 9) A high-pressure fuel pump provided by sandwiching restriction parts (81-83) for restricting deformation of the block 9 to the block side . The high-pressure fuel pump according to any one of claims 1 to 9 ,
The bearing members (7-9) have high surface pressure generating portions (61-63) that receive a load from the camshafts (4-6),
The high-pressure fuel pump , wherein the deformation relief portion is provided only on the back side of the high surface pressure generating portion (61-63) . (A) pistons (1-3) that reciprocate in the cylinder hole and pressurize and feed fuel;
(B) camshafts (4-6) for driving the pistons (1-3) in the moving direction;
(C) a block (11-13) having an accommodation hole for accommodating the camshaft (4-6) so as to be movable in the rotation direction;
(D) a cylindrical bearing member (7-9) fixed to the housing hole wall surface of the block (11-13) and supporting the camshaft (4-6) slidably in the rotational direction;
(E) It is provided between the block (11-13) and the bearing member (7-9), and receives a load from the camshaft (4-6) to generate a high surface pressure. A deformation relief portion for allowing deformation of the bearing members (7-9);
With
The bearing members (7-9) have high surface pressure generating portions (61-63) that receive a load from the camshafts (4-6),
The high-pressure fuel pump, wherein the deformation relief portion is provided only on the back side of the high surface pressure generating portion (61-63). The high-pressure fuel pump according to any one of claims 1 to 11,
The camshaft has a cam (4) having a circular cross section perpendicular to the rotation axis direction,
The high pressure fuel pump according to claim 1, wherein the cam (4) is provided on the camshaft (5, 6) so as to be eccentric with respect to a rotation axis direction of the camshaft (5, 6). The high-pressure fuel pump according to claim 12,
The block is a cam ring (11) that revolves around the cam (4),
The housing hole is a cam housing hole for rotatably housing the cam (4). The high-pressure fuel pump according to claim 13,
The piston is
A high-pressure fuel pump characterized in that it is a plunger (1-3) slidingly contacting the outer surface of the cam ring (11) and reciprocatingly following the revolution of the cam ring (11). The high-pressure fuel pump according to claim 12,
The camshaft has two journals (5, 6),
The high pressure fuel pump, wherein the two journals (5, 6) are provided on both sides of the cam (4) in the rotation axis direction. The high pressure fuel pump according to claim 15,
The block is a housing (12, 13) in which a cam chamber (20) is formed.
The high-pressure fuel pump is characterized in that the accommodation hole is a journal accommodation hole that rotatably accommodates at least one of the two journals (5, 6). The high-pressure fuel pump according to any one of claims 1 to 16,
The deformation relief portion is
A high pressure fuel pump provided by sandwiching an elastic body between the block (11-13) and the bearing member (7-9). The high-pressure fuel pump according to any one of claims 1 to 17,
A high-pressure fuel pump comprising a lubricating oil supply means for supplying lubricating oil to a sliding portion between the camshaft (4-6) and the bearing member (7-9).

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