JP2008163816A - Cam mechanism mounting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve seizure resistance and abrasion resistance in a tappet and a roller, even if a direct sliding type is adopted. <P>SOLUTION: This tappet 36 has a lubricating oil introducing part 41 expanding a clearance with the roller 37 in the rotatingly entering direction of a roller outer peripheral surface more than a direct sliding range A. This lubricating oil introducing part 41 introduces fuel to the vicinity of the direct sliding range A by communicating with an external part in an under surface of the tappet 36, and presents a shape of cutting out a part of a roller holding hole 38. When the roller 37 rotates in response to operation of a high pressure fuel pump, lubricating oil introduced inside the lubricating oil introducing part 41 from the external part of the tappet 36, is pressurized toward a directly sliding part of the roller 37 and the tappet 36 by torque of the roller 37, and the lubricating oil is supplied to the directly sliding part of the roller 37 and the tappet 36. Thus, even if the direct sliding type is adopted, the abrasion resistance of the roller 37 and the tappet 36 can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cam mechanism mounting device in which a roller and a tappet are interposed between a cam crest and a driven object, and particularly relates to a technique in which a roller and a tappet slide directly.

(Conventional technology)
Conventionally, a high-pressure fuel pump (supply pump) is known as an example of a cam mechanism mounting device in which a roller and a tappet are interposed between a cam crest and a driven object.
A high-pressure fuel pump for a vehicle includes a camshaft driven by an engine, and a plunger (an example of an object to be driven) driven by a cam peak height displacement associated with the rotation of the camshaft, and the plunger is driven by the camshaft. By reciprocating, the volume of the pressurizing chamber at the end of the plunger fluctuates to perform fuel suction and pressure feeding.

As shown in FIGS. 9 and 10, a roller J3 and a tappet J4 are disposed between the cam crest J1 and the plunger J2.
The tappet J4 is supported so as to be able to reciprocate in the axial direction, and abuts against the plunger J2 to reciprocate integrally with the plunger J2.
On the other hand, the roller J3 has a cylindrical shape and is rotatably supported by the tappet J4, and rotates along the cam crest J1.
As a support structure of the roller J3 by the tappet J4, a pin J5 is used for the rotating shaft of the roller J3 shown in FIG. 9, and the pin J5 is supported by the tappet J4, and the outer peripheral surface of the roller J3 shown in FIG. There is known a direct sliding type (see Patent Documents 1 and 2) that slides directly.

(Problems of conventional technology)
In the pin type, the outer peripheral surface of the roller J3 is exposed to the fuel except for the portion that slides directly with the tappet J4. Therefore, the oil film can be easily held on the outer peripheral surface of the roller J3 and the seizure resistance is high. However, the physique of the tappet J4 is increased, the number of parts is increased, and the number of assembling steps is increased. Therefore, there is an increasing demand for using a direct sliding type.

The direct sliding type can reduce the size of the tappet J4 and the number of parts, but has the following problems. In the following description, for convenience of explanation, the upper side (plunger J2 side) in FIG. 10 is described as the upper side, and the lower side (camshaft J6 side) in FIG.
When assembling the tappet J4 and the roller J3 to the high-pressure fuel pump, it is necessary to prevent the roller J3 from dropping from the tappet J4.
Therefore, the tappet J4 is provided with a roller holding hole J7 into which the roller J3 is inserted, and the structure in which the tappet J4 holds the roller J3 by the roller holding hole J7 is adopted to prevent the roller J3 from falling off the tappet J4. Proposed. The roller holding hole J7 is a substantially cylindrical round hole formed in parallel with the rotation axis of the camshaft J6, and is formed so that the lower side of the outer peripheral surface of the roller J3 is exposed below the tappet J4. The sliding diameter dimension of the roller holding hole J7 (inner diameter dimension of the round hole) is set to be larger by the sliding clearance than the outer diameter dimension of the roller J3.

Specifically, the inner peripheral surface of the roller holding hole J7 is (i) a direct sliding where the tappet J4 and the roller J3 slide directly under the lift load by the cam crest J1 and the fuel pressurization load by the plunger J2. The range A is divided into (ii) a roller holding range different from the direct sliding range A.
The direct sliding range A is the upper part of the roller holding hole J7 when the roller J3 is viewed from the axial direction (see FIG. 10), and the roller holding range is from “the end of the direct sliding range A” to “the roller holding hole J7. Up to “lower opening (opening end exposing roller J3 downward)”.

Since the direct sliding range A is a portion that receives the lift load of the cam crest J1 and the fuel pressure load of the plunger J2, the contact surface pressure between the roller J3 and the tappet J4 is high.
In order to prevent seizure of the tappet J4 and the roller J3 in the direct sliding range A, it is necessary to supply lubricating oil to the direct sliding range A. However, in the case of the direct sliding type, a long roller holding range is interposed between the lower opening of the roller holding hole J7 and the direct sliding range A. This long roller holding range is a fine clearance between the roller J3 and the roller holding hole J7. For this reason, the direct sliding type has a structure in which the lubricating oil supply capability to the direct sliding range A is low.

In this way, the direct sliding type has a low lubricating oil supply capability to the direct sliding range A and has a structure that makes it difficult to hold an oil film between the roller J3 and the tappet J4. There was a problem of inferiority.
In the above, the problems of the prior art have been described by taking the high pressure fuel pump as an example. However, the type in which the roller J3 and the tappet J4 slide directly and the roller J3 is held by the roller holding hole J7 is the same problem as described above. Will occur.
Japanese Patent Application Laid-Open No. 2004-218459 JP 2004-324535 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a cam mechanism mounting device that can improve the seizure resistance and wear resistance of a tappet and a roller even if it is a direct sliding type. Is in the provision of.

[Means of claim 1]
The tappet of the cam mechanism mounting device adopting the means of claim 1 has a wider clearance with the roller in the rotational approach direction of the roller outer peripheral surface than the direct sliding range in which the roller slides directly, and communicates with the outside of the tappet. A lubricating oil introduction section is provided.
By providing the lubricating oil introducing portion, the lubricating oil enters the portion where the roller and the tappet slide directly by the rotation of the roller. In this way, since the lubricating oil is supplied to the portion where the roller and the tappet directly slide, the seizure resistance and wear resistance of the tappet and the roller can be improved even in the direct sliding type.

[Means of claim 2]
The lubricating oil introducing portion of the cam mechanism mounting device adopting the means of claim 2 is provided in a shape in which the clearance continuously spreads in the rotation approach direction of the outer peripheral surface of the roller.
Thereby, the rotation of the roller increases the pressure of the lubricating oil that enters the portion where the roller and the tappet directly slide. As a result, the oil film holding ability of the portion where the roller and the tappet directly slide is further increased, and the seizure resistance and wear resistance of the tappet and the roller can be further improved.

[Means of claim 3]
If a part of the lubricating oil introduction portion is within the direct sliding range, the sliding area between the roller and the tappet is reduced by the lubricating oil introduction portion within the direct sliding range. Then, the contact surface pressure between the roller and the tappet increases, and there is a possibility that the lubricating oil introduction portion becomes a starting point of seizure.
Therefore, in the cam mechanism mounting apparatus employing the means of claim 3, the end portion on the direct sliding range side of the lubricating oil introducing portion is provided outside the direct sliding range.
As a result, it is possible to avoid the problem that the lubricating oil introduction portion provided for the purpose of improving the seizure resistance of the tappet and the roller becomes the starting point of seizure.

[Means of claim 4]
The lubricating oil introducing portion in the cam mechanism mounting device adopting the means of claim 4 guides the lubricating oil to a portion where the contact surface pressure between the roller and the tappet is high in the direct sliding range. That is, for example, when the contact surface pressure is highest in the central portion of the roller in the rotation axis direction in the direct sliding range, the lubricant oil introduction portion is provided in the central portion of the tappet in the rotation axis direction of the roller. .
By providing in this way, lubricating oil can be efficiently supplied to the part where the contact surface pressure is particularly increased, and the seizure resistance and wear resistance of the tappet and the roller can be efficiently increased.

[Means of claim 5]
The cam mechanism mounting device adopting the means of claim 5 is a high-pressure fuel pump that pressurizes and discharges fuel by the displacement of the height of the cam crest, and the driven object sucks and pressurizes the fuel by reciprocating displacement. It is a plunger.
And by combining with any one of the means of the said Claims 1-4, even if a high-pressure fuel pump is a direct sliding type, the seizure resistance and abrasion resistance of a tappet and a roller can be improved.

A cam mechanism mounting device (for example, a high-pressure fuel pump or the like) according to the best mode 1 includes a camshaft having a cam peak whose height is displaced by rotation, and a driving object (for example, a reciprocating drive by a height displacement of the cam peak) , A plunger, etc., and a tappet that comes into contact with the driven object, and a roller that is rotatably supported by the tappet and has a cylindrical shape that comes into contact with the cam crest.
The tappet is provided with a roller holding hole for holding the roller slidably in a state where a part of the outer peripheral surface of the roller is exposed to the outside of the tappet.
Furthermore, the tappet has a rotational approach direction on the outer peripheral surface of the roller rather than the direct sliding range in which the roller directly slides (the camshaft rotates in both directions and the roller rotates in both directions is the direct sliding range in both directions). In addition, a lubricating oil introducing portion that widens the clearance with the roller and communicates with the outside of the tappet is provided.

A first embodiment in which the present invention is applied to a high-pressure fuel pump (supply pump) will be described with reference to FIGS. In the first embodiment, a schematic configuration of a high-pressure fuel pump is first described with reference to FIG. 4, and then a main part to which the present invention is applied will be described with reference to FIGS.
The high pressure fuel pump is applied to, for example, a common rail type fuel injection device of a diesel engine (hereinafter referred to as an engine), and pressurizes fuel supplied from a fuel tank via a low pressure pump (feed pump) to a high pressure. This is a fuel pump that supplies pressure to the tank.
In this embodiment, for the sake of explanation, the camshaft side (lower side in FIG. 4) of the high-pressure fuel pump will be described below, and the solenoid valve side (upper side of FIG. 4) will be described as upper. However, this embodiment is limited to the actual mounting direction. It is not something.

The high-pressure fuel pump includes a pump housing 1 that is fixed to an engine or the like, and a cylinder body 2 that is coupled to the pump housing 1 while being inserted into the pump housing 1.
A cam chamber 3 is formed on the lower side of the pump housing 1. The cam chamber 3 accommodates a cam shaft 4 driven by an engine. A cam crest 5 is formed on the camshaft 4 integrally with the camshaft 4. A plurality of cam ridges 5 are formed in the circumferential direction (three in this embodiment) in order to reciprocate a plunger 7 to be described later a plurality of times (three in this embodiment) when the camshaft 4 makes one rotation. Yes.

  The cylinder body 2 is formed with a cylindrical cylinder hole 6 extending in the vertical direction. Inside the cylinder hole 6, a plunger 7 having a cylindrical bar shape is supported so as to be reciprocally slidable in the vertical direction through a minute clearance, and the fuel is sucked and added to the cylinder hole 6 at the upper end of the plunger 7. A pressurizing chamber (fuel compression chamber) 8 for performing pressure is formed. The upper end of the cylinder hole 6 communicates with the fuel supply side (low pressure side) via the electromagnetic valve 9, and the pressurizing chamber 8 and the fuel supply side are opened and closed by the electromagnetic valve 9.

  A fuel supply pipe 11 that receives low-pressure fuel from the outside (feed pump) is connected to the side surface of the pump housing 1, and the low-pressure fuel supplied to the fuel supply pipe 11 is between the pump housing 1 and the cylinder body 2. It is supplied to an annular fuel reservoir 12 formed therebetween. On the other hand, the solenoid valve 9 is fixed to the top of the cylinder body 2, and an annular low pressure chamber 13 is formed between the solenoid valve 9 and the cylinder body 2. The cylinder body 2 is formed with a low-pressure fuel passage 14 that communicates the fuel reservoir 12 and the low-pressure chamber 13. As a result, the low pressure fuel supplied to the fuel supply pipe 11 is guided to the low pressure chamber 13 around the electromagnetic valve 9.

  A fuel discharge pipe 15 that discharges high-pressure fuel pressurized in the pressurizing chamber 8 to the outside (common rail) is connected to the side surface of the pump housing 1. The cylinder body 2 is formed with a high-pressure fuel passage 16 that connects the pressurizing chamber 8 and the fuel discharge pipe 15, and the fuel pressurized in the pressurizing chamber 8 passes through the high-pressure fuel passage 16 to the fuel discharge pipe. 15 is discharged. A discharge valve 17 that opens at a predetermined pressure or higher and discharges a fuel pressure higher than a predetermined pressure to the outside is provided inside the fuel discharge pipe 15.

The electromagnetic valve 9 is a combination of a low pressure chamber 13 around the electromagnetic valve 9, a valve 21 that communicates and shuts off the pressurizing chamber 8 at the upper end of the plunger 7, and an electromagnetic actuator 22 that drives the valve 21 to open and close. Is.
The valve 21 includes a valve body 23 and a valve body 24. When the valve body 24 is driven upward, the communication between the low pressure chamber 13 and the pressurizing chamber 8 is interrupted, and when the valve body 24 is driven downward. The low pressure chamber 13 and the pressurizing chamber 8 are communicated.

  The electromagnetic actuator 22 includes a solenoid (electromagnet) 25, an armature 26, a return spring 27, and the like. When the solenoid 25 is energized through a connector 28 provided on the upper portion, the armature 26 coupled to the valve body 24 is As a result of magnetic attraction upward, the communication between the low pressure chamber 13 and the pressurizing chamber 8 is blocked. Further, when energization is stopped, the valve body 24 is driven downward by the action of the return spring 27, and the low pressure chamber 13 and the pressurizing chamber 8 communicate with each other.

  The solenoid valve 9 (solenoid 25 of the solenoid actuator 22) is energized and controlled by an ECU (abbreviation of engine control unit: controller: not shown), and the ECU controls the energization timing of the solenoid valve 9. Thus, the amount of pressurized fuel in the pressurizing chamber 8 is controlled, and the flow rate of fuel discharged from the fuel discharge pipe 15 to the common rail is adjusted.

  The lower end of the plunger 7 is coupled to the lower sheet 32 by a plunger head 31 having an enlarged diameter. The upper surface of the lower seat 32 is in contact with the lower end of the coil spring 33 in the axial direction in the pump housing 1, and the lower end surface of the plunger 7 is pressed against the upper surface of a tappet 36 described later by the urging force of the coil spring 33. It touches. The upper end of the coil spring 33 is in contact with the upper seat 34, and the upper seat 34 is restricted from moving upward by the cylinder body 2.

  A tappet cylinder 35 is formed in the pump housing 1 above the cam chamber 3. Inside the tappet cylinder 35, a tappet 36 is supported so as to be slidable back and forth in the vertical direction. The side surfaces of the tappet cylinder 35 and the tappet 36 are provided with parallel surfaces extending along the axial direction (vertical direction), and the tappet 36 is not rotatable about the axial direction.

Between the tappet 36 and the cam mountain 5, a roller 37 that is rotatable along the cam mountain 5 is disposed. The roller 37 has a cylindrical shape and is rotatably supported by the tappet 36, and the roller 37 always abuts against the cam crest 5 by the urging force of the coil spring 33.
Specifically, as shown in FIG. 4, a roller holding hole 38 that supports the roller 37 so as to freely rotate and slide is formed on the lower side of the tappet 36. The roller holding hole 38 is a circular hole that holds the roller 37 through a sliding clearance, and allows the roller 37 to slide freely with the lower part of the outer peripheral surface of the roller 37 exposed below the lower surface of the tappet 36. Hold.
The penetrating shaft of the roller holding hole 38 (the rotating shaft of the roller 37) is formed in parallel with the rotating shaft of the camshaft 4 so that the straight portion of the cam crest 5 and the straight portion of the roller 37 coincide with each other. Yes.

  4, the drive shaft core of the plunger 7, the drive shaft core of the tappet 36, the rotation shaft core of the roller 37, and the rotation shaft core of the camshaft 4 are provided so as to be aligned on the vertical axis. . As a result, the height displacement of the cam crest 5 accompanying the rotation of the camshaft 4 is transmitted to the plunger 7 via the roller 37 and the tappet 36 on the extension line of the substantially central axis of the plunger 7.

[Features of Example 1]
The high-pressure fuel pump is an example of a cam mechanism mounting device, and as shown in the above configuration, a tappet 36 and a roller 37 are disposed between the cam crest 5 and the plunger 7 (an example of an object to be driven). The height displacement of the cam crest 5 is transmitted to the plunger 7 via the roller 37 and the tappet 36.
Further, as described above, the roller 37 is rotatably supported by the roller holding hole 38 formed in the tappet 36, and the outer peripheral surface of the roller 37 is the upper curved surface of the roller holding hole 38 (within the direct sliding range A). ) To slide directly.
On the other hand, the inside of the pump housing 1 (the inside of the cam chamber 3 and the tappet cylinder 35) is filled with fuel through a minute clearance between the cylinder hole 6 and the plunger 7, a through hole 36a formed in the tappet 36, and the like. Each part is lubricated by the fuel filled in the pump housing 1.

Here, the direct sliding range A in the roller holding hole 38 will be described with reference to FIG.
The roller holding hole 38 is a circular hole for slidingly holding the roller 37, but the range in which the roller 37 actually slides during operation of the high-pressure fuel pump is limited. The portion where the roller 37 actually slides during the operation of the high-pressure fuel pump is within a predetermined range due to the change in the combined force Z at the contact portion between the cam peak 5 and the roller 37 as the cam peak 5 is displaced in height. It changes with.
Specifically, a tangential force X in the tangential direction at the contact portion between the cam crest 5 and the roller 37, a lift load due to the cam crest 5, and a vertical stress Y due to a fuel pressurizing load due to the plunger 7 are applied to the roller 37. Therefore, the combined force Z is applied to the roller 37 from the contact portion with the cam crest 5 as a starting point. When the camshaft 4 rotates and the height of the cam crest 5 is displaced, the contact portion between the cam crest 5 and the roller 37 changes, and the tangential force X and the vertical stress Y change to change the direction of the resultant force Z. Since the size changes, the portion where the roller 37 and the tappet 36 slide directly changes.
A change range of a portion where the roller 37 and the tappet 36 slide directly during one rotation of the camshaft 4 (specifically, during one cycle of displacement of the cam crest 5) is referred to as a direct sliding range A. .
In addition, among the circular holes forming the roller holding hole 38, a circular hole inner peripheral surface different from the direct sliding range A is referred to as a roller holding range.

The tappet 36 is provided with a lubricating oil introducing portion 41 having a larger clearance with the roller 37 in the rotation approach direction (right side of the direct sliding range A in FIG. 1) of the roller outer peripheral surface than the direct sliding range A. Yes. This lubricating oil introduction part 41 communicates with the outside (inside the pump housing 1 filled with fuel) on the lower surface of the tappet 36 and guides the fuel directly to the vicinity of the sliding range A. As shown in FIG. The roller holding hole 38 is partially cut out.
An example of a specific method for forming the lubricating oil introducing portion 41 is disclosed. First, the roller holding hole 38 is formed in the tappet 36 by cutting. Thereafter, a part of the roller holding hole 38 is widened by cutting to form the lubricating oil introducing portion 41. This forming method is an example, and the lubricating oil introducing portion 41 may be formed using other forming methods. Moreover, the shape of the lubricating oil introduction part 41 shown in FIG. 2 is an example for description, and other shapes such as a chamfered shape at the corner of the lubricating oil introduction part 41 may be used.

Here, when the plunger 7 pressurizes fuel, a concentrated load (pressurized load of fuel) is applied from the plunger 7 to the central portion (plunger contact portion) of the upper surface of the tappet 36. Due to the concentrated load received at the plunger contact portion, the contact surface pressure between the roller 37 and the tappet 36 is highest at the central portion of the roller 37 in the rotation axis direction.
In view of this, the lubricating oil introducing portion 41 of this embodiment directs the lubricating oil in the direct sliding range A in the vicinity of the portion where the contact surface pressure between the roller 37 and the tappet 36 is high (the central portion in the rotational axis direction of the roller 37). As shown in FIG. 2, a lubricating oil introduction portion 41 is formed at an intermediate portion of the roller 37 in the rotation axis direction so that the guide can be reliably conducted. As a result, the lubricating oil can be positively supplied to a portion having a high contact surface pressure, and the roller holding range is left on both sides of the lubricating oil introduction portion 41 (both sides in the rotation axis direction of the roller 37). There is no problem that the roller 37 falls off the tappet 36 when the 36 is assembled.

  Moreover, the lubricating oil introduction part 41 is provided in the shape where the clearance of the roller 37 and the tappet 36 spreads continuously toward the rotation approach direction of a roller outer peripheral surface. The lubricating oil introducing portion 41 of the first embodiment is provided on an inwardly curved surface. Specifically, as shown in FIG. 3, the curvature R <b> 1 forming the lubricating oil introducing portion 41 is larger than the curvature R <b> 2 of the roller holding hole 38. The curvature R2 of the roller holding hole 38 is set to a curvature that is extremely slightly larger (sliding clearance) than the curvature of the outer peripheral surface of the roller 37 (the curvature due to the roller diameter D).

  Further, as shown in FIG. 1, the end of the lubricating oil introduction portion 41 on the side close to the direct sliding range A (starting point P of the clearance spread) is provided outside the direct sliding range A. It is provided very close to the end of the moving range A. In addition, the design distance (length at the time of shipment) between the end portion of the lubricating oil introduction portion 41 closer to the direct sliding range A (starting point P of the clearance spread) and the end portion of the direct sliding range A is Even if the direct sliding range A expands due to wear by performing the operation at the upper limit of the design, the direct sliding range A is provided at a distance that does not reach the lubricating oil introducing portion 41. The design distance is between the roller 37 and the tappet 36. It is appropriately set depending on the material (hardness, etc.) and shape (size, etc.).

(Operation of Example 1)
When the camshaft 4 is rotated by the operation of the engine and the high-pressure fuel pump is operated, the height of the cam crest 5 is displaced vertically on the extended line of the central axis of the plunger 7.
In the process of increasing the height of the cam peak 5, the height displacement of the cam peak 5 is transmitted to the plunger 7 via the roller 37 and the tappet 36, and the plunger 7 moves up and the fuel supplied to the pressurizing chamber 8 is removed. Pressurize.
On the contrary, in the process in which the height of the cam crest 5 decreases, the plunger 7, the tappet 36, and the roller 37 are lowered by the biasing force of the coil spring 33, and the fuel is sucked into the pressurizing chamber 8.

During the operation of the high pressure fuel pump, the roller 37 rotates along the cam mountain 5 as the camshaft 4 rotates, and the roller 37 and the tappet 36 slide directly within the direct sliding range A. When the roller 37 rotates, the outer peripheral surface of the roller 37 repeatedly rotates in the direct sliding range A → the roller holding range on the left side of FIG. 1 → the outside of the tappet 36 → the roller holding range on the right side of FIG. .
For this reason, the lubricating oil (fuel) guided from the outside of the tappet 36 to the inside of the lubricating oil introducing portion 41 is pressurized toward the portion where the roller 37 and the tappet 36 slide directly by the rotational force of the roller 37. The pressure of the lubricating oil toward the part where the roller 37 and the tappet 36 slide directly increases.
As a result, the lubricating oil introduced to the lubricating oil introducing portion 41 enters the portion where the roller 37 and the tappet 36 slide directly by the rotation of the roller 37, and the lubricating oil is applied to the portion where the roller 37 and the tappet 36 directly slide. Supplied.

(Effect of Example 1)
As described above, the high-pressure fuel pump according to the first embodiment includes the lubricating oil introduction portion 41 in the rotational approach direction of the roller outer peripheral surface rather than the direct sliding range A of the tappet 36, and the roller 37 and the tappet are rotated by the rotation of the roller 37. Lubricating oil enters the part where 36 slides directly. In this way, since the lubricating oil is supplied to the portion where the roller 37 and the tappet 36 directly slide, the seizure resistance of the roller 37 and the tappet 36 can be improved even if the high pressure fuel pump is a direct sliding type. Thus, the wear resistance of the roller 37 and the tappet 36 can be improved.

  Further, in the first embodiment, the lubricating oil introducing portion 41 is provided in a shape in which the clearance continuously spreads in the rotation approach direction of the outer peripheral surface of the roller, so that the roller 37 and the tappet 36 are directly connected by the rotation of the roller 37. The pressure of the lubricating oil entering the sliding part increases. As a result, the oil film holding ability of the portion where the roller 37 and the tappet 36 directly slide can be further increased, and the seizure resistance and wear resistance of the roller 37 and the tappet 36 can be further improved.

  Further, in the first embodiment, the lubricating oil introducing portion 41 directly guides the lubricating oil to the central portion in the rotation axis direction of the roller 37 in the sliding range A (the portion where the contact surface pressure between the roller 37 and the tappet 36 is high). As a result, the central portion of the direct sliding range A where the contact surface pressure is particularly high can be efficiently lubricated, and the seizure resistance and wear resistance reliability of the roller 37 and the tappet 36 can be improved.

On the other hand, if a part of the lubricating oil introduction part 41 is in the direct sliding range A, the sliding area between the roller 37 and the tappet 36 is reduced by the lubricating oil introducing part 41 existing in the direct sliding range A, and the direct sliding There is a possibility that the lubricating oil introduction part 41 in the moving range A becomes a starting point of seizure.
On the other hand, in the first embodiment, since the end portion of the lubricating oil introducing portion 41 on the side close to the direct sliding range A is provided outside the direct sliding range A, it is provided for the purpose of improving seizure resistance. In addition, the lubricating oil introducing portion 41 does not become a starting point for seizure.

A second embodiment will be described with reference to FIG. In the following embodiments, the same reference numerals as those in the first embodiment denote the same functional objects.
In the first embodiment, as an example in which the lubricant introduction portion 41 continuously spreads in the rotation approach direction of the roller outer peripheral surface, the shape of the lubricant introduction portion 41 formed in the tappet 36 is provided on the inward R curved surface. showed that.
On the other hand, in the second embodiment, the surface shape forming the lubricating oil introducing portion 41 is provided on a straight plane, and the lubricating oil introducing portion 41 is continuously formed toward the rotational approach direction of the roller outer peripheral surface as in the first embodiment. It has been expanded to. Even if it provides in this way, the same effect as Example 1 can be acquired.

A third embodiment will be described with reference to FIG.
In this third embodiment, the shape of the lubricating oil introducing portion 41 formed in the tappet 36 is provided on the outwardly curved surface, and the lubricating oil introducing portion 41 is continuously directed toward the rotational approach direction of the roller outer peripheral surface as in the first embodiment. It has been expanded. Even if it provides in this way, the same effect as Example 1 can be acquired.

A fourth embodiment will be described with reference to FIG.
In the fourth embodiment, a step portion is formed in the lubricating oil introducing portion 41 to directly guide the lubricating oil to the vicinity of the sliding range A. Even if the lubricating oil introduction part 41 has a stepped shape, the lubricating oil directly guided to the vicinity of the sliding range A is supplied to the direct sliding part of the roller 37 and the tappet 36 by the rotational force of the roller 37. The seizure resistance and wear resistance of the roller 37 and the tappet 36 can be improved as compared with the direct sliding type of technology.

A fifth embodiment will be described with reference to FIG.
In each of the above-described embodiments, the example in which the lubricating oil introducing portion 41 is formed only in one of the direct sliding ranges A (only in the rotation approach direction of the roller outer peripheral surface) has been shown.
On the other hand, in the fifth embodiment, the lubricating oil introducing portion 41 is formed in both the direct sliding range A (the rotation approach direction and the rotation exit direction of the roller outer peripheral surface).
Thus, by providing the lubricating oil introduction part 41 in both of the direct sliding ranges A, designation | designated of an assembly direction is lose | eliminated and assembly | attachment property can be improved.
Moreover, it can be used for a high-pressure fuel pump in which the rotation direction of the camshaft 4 is different, and the versatility is enhanced, so that the cost can be suppressed.

[Modification]
In the above-described embodiment, an example in which one lubricating oil introduction portion 41 is formed in the rotation approach direction of the outer peripheral surface of the roller in the direct sliding range A is shown, but two or more may be provided.
In the above embodiment, the type in which the communication between the pressurizing chamber 8 and the low pressure chamber 13 is cut off when the solenoid valve 9 is energized is shown as an example. It may be a high-pressure fuel pump.
In the above embodiment, the pressurization chamber 8 and the low pressure chamber 13 are opened and closed by the electromagnetic valve 9. However, the pressurization chamber 8 and the low pressure chamber are formed by other electric actuator valves such as a piezo valve using a piezo actuator. 13 may be opened and closed.
Further, the present invention may be applied to a high-pressure fuel pump (for example, a row type pump) that varies the fuel discharge pressure by a mechanical configuration (rack & pinion or the like) without using an electric actuator.

In the above embodiment, the example in which the present invention is applied to the high-pressure fuel pump that performs suction and metering of the pressurizing chamber 8 by the single solenoid valve 9 has been shown, but the metering valve (SCV or the like) and the suction valve (reverse) The present invention may be applied to a high-pressure fuel pump provided with a stop valve and the like separately.
An example of a specific metering valve is shown. The metering valve is an electromagnetic metering valve that opens and closes by a solenoid. By controlling the energization of the solenoid (for example, duty ratio control), the passage area of the fuel flow path that guides fuel to the pressurizing chamber 8 is changed. The predetermined fuel is sent to the pressurizing chamber 8. An example of a specific intake valve is shown. The suction valve applies a biasing force (valve closing force) to the valve by a spring, and opens when the fuel pressure on the low pressure side (low pressure fuel supply side) becomes greater than a predetermined pressure from the inside of the pressurizing chamber 8. is there.
In the above embodiment, the example in which the present invention is applied to the high-pressure fuel pump is shown. However, the driven object is not limited to the plunger 7 of the high-pressure fuel pump, and may be a plunger other than the fuel pump. A member that does not reciprocate linearly (for example, an arm member that reciprocates an arc) may be used. That is, the present invention may be applied to cam mechanism mounting devices (for example, industrial robots) other than the fuel pump.

(Example 1) which is the schematic which looked at the principal part of the high-pressure fuel pump from the roller rotating shaft direction. (Example 1) which is a cross-sectional perspective view of a tappet. (Example 1) which is explanatory drawing which shows the curvature of a lubricating oil introduction part. (Example 1) which is sectional drawing of a high pressure fuel pump. (Example 2) which is the schematic which looked at the principal part of the high-pressure fuel pump from the roller rotating shaft direction. (Example 3) which is the schematic which looked at the principal part of the high-pressure fuel pump from the roller rotating shaft direction. (Example 4) which is the schematic which looked at the principal part of the high-pressure fuel pump from the roller rotating shaft direction. (Example 5) which is the schematic which looked at the principal part of the high-pressure fuel pump from the roller rotating shaft direction. It is the schematic which looked at the principal part of the high-pressure fuel pump from the roller rotating shaft direction, and the schematic sectional view which looked from the perpendicular direction of the roller rotating shaft (pin type conventional example). It is the schematic which looked at the principal part of the high-pressure fuel pump from the roller rotating shaft direction (direct sliding type conventional example).

Explanation of symbols

4 Camshaft 5 Cam crest 7 Plunger (driven object)
36 Tappet 37 Roller 38 Roller holding hole 41 Lubricating oil introduction part A Direct sliding range P Starting point (end near the direct sliding range in the lubricating oil introduction part)

Claims (5)

It is arranged between a camshaft having a cam crest whose height is displaced by rotation and a driving object that is driven to reciprocate by the height displacement of the cam crest,
A cam mechanism mounting device comprising: a tappet that abuts against the driving object; and a roller that is rotatably supported by the tappet and has a cylindrical shape that abuts against the cam crest.
The tappet is
In a state where a part of the outer peripheral surface of the roller is exposed to the outside of the tappet, the roller holding hole for holding the roller directly slidable,
It is characterized by comprising a lubricating oil introduction part that widens the clearance with the roller and communicates with the outside of the tappet in the rotational approach direction of the outer peripheral surface of the roller rather than the direct sliding range in which the roller directly slides. Cam mechanism mounting device. In the cam mechanism mounting device according to claim 1,
The cam mechanism mounting device according to claim 1, wherein the lubricating oil introduction portion is provided in a shape in which the clearance continuously spreads in a rotation approach direction of the outer peripheral surface of the roller. In the cam mechanism mounting device according to claim 1 or 2,
The cam mechanism mounting device characterized in that the end portion on the direct sliding range side of the lubricating oil introducing portion is provided outside the direct sliding range. In the cam mechanism mounting device according to any one of claims 1 to 3,
The cam mechanism mounting device characterized in that the lubricating oil introducing section guides the lubricating oil to a portion where a contact surface pressure between the roller and the tappet is high in a direct sliding range. In the cam mechanism mounting device according to any one of claims 1 to 4,
This cam mechanism mounting device is a high-pressure fuel pump that pressurizes and discharges fuel by the height displacement of the cam crest,
The cam mechanism mounting device, wherein the driven object is a plunger that sucks and pressurizes fuel by reciprocating displacement.

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