JP2000073717A - Jig for exchanging shim - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the jig for exchanging a shim having a versatility capable of coping with various engines and without removing a cam shaft and journal cap, which can install easily under such state that the engine is mounted and expand between a valve lifter and a cam surely and easily. SOLUTION: The jig for exchanging a shim 1 is composed of a main body 2, arm 3 and turning means 4. Lateral direction movement restraint parts 10, 20 for restraining the movement to the lateral direction for a cylinder head 50 by crossing with the reciprocation movement direction of a valve lifter 64 and telecoping to the direction orthogonally crossing with the axial core direction of a cam shaft 60 and an upper direction movement restraint part 19 for interposing between the cam shaft 60 and valve lifter 64 and restraining the movement to the upper direction for the cylinder head 50 are provided on the main body 2. The arm 3 has an engaging part 33 whose basic end side is pivoted to the main body 2 and which can engage with a cam facing surface 65 at the turning tip side. The turning means 4 has such structure that the valve lifter 64 turns the turning tip side of the arm 3 to the valve opening direction separating from the cam shaft 60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shim changing jig, and more particularly to a method for changing a shim for adjusting a valve clearance interposed between a cam and a valve lifter of an engine having a direct-acting valve operating mechanism. The present invention relates to a shim replacement jig used for a jig.

[0002]

2. Description of the Related Art As a valve operating mechanism of an engine, there is a direct-acting valve operating mechanism in which a valve lifter is moved up and down by a cam to open and close a valve. The valve is normally biased in the valve closing direction by a valve spring, and the cam is moved in the valve opening direction by pushing down the valve lifter. A shim is provided between the cam and the valve lifter to finely adjust the valve clearance between the cam and the valve lifter.

[0003] The shim is loaded in a recess formed in a cam facing surface facing the cam of the valve lifter, and comes into sliding contact with the cam by rotation of the cam shaft. The shim can be replaced with one having a different thickness, and the valve is securely seated on the valve seat when the valve is closed by finely adjusting the valve clearance between the cam and the valve lifter.

However, since the valve lifter is always urged in the valve closing direction by the valve spring, in order to replace the shim, the space between the valve lifter and the cam must be widened, and the shim must be replaced between them.

Therefore, for the shim replacement work,
The valve lifter must be pressed down against the urging force of the valve spring to form a gap between the valve lifter and the cam where the shim can be inserted and removed.

However, since most of the cam-facing surface of the valve lifter is occupied by the shim, the portion where only the valve lifter can be pushed down on the cam-facing surface is very narrow, and the work of pushing down the valve lifter in the valve opening direction is performed. Was not easy.

Therefore, in order to facilitate such work,
Conventionally, various dedicated jigs have been proposed. For example, there is a jig in which one is engaged with the outer edge portion of the valve lifter on the cam facing surface side, the other is engaged with the camshaft, and the gap between them is expanded to push down the valve lifter to form a gap.

However, the operation of engaging one of the jigs with the outer edge portion on the cam facing surface side is performed in a narrow working space between the camshaft and the valve. Therefore, some skill was required, and the use of such a jig was not something that could be easily performed by anyone.

Therefore, as a jig capable of performing shim changing work more easily and surely, for example, Japanese Unexamined Patent Publication No.
Japanese Patent Publication No. 270416 discloses a jig of a type in which a part of the jig is fixed to a cylinder head to perform an operation.
According to the jig described in the publication, the journal cap of the camshaft located in the vicinity of the valve lifter is removed, and the dowel pins for positioning the journal cap are applied for positioning and fixing the jig, thereby positioning the jig main body. A jig for fixing and expanding between the valve lifter and the cam is shown.

[0010] According to this jig, the jig is securely positioned by mounting the jig body instead of the journal cap, and a part of the jig is easily engaged with the outer edge portion of the valve lifter on the cam facing surface side. It is described that they can be combined.

[0011]

However, since the above-mentioned jig employs a method using a dowel pin for positioning the journal cap, it is necessary to use a jig specifically designed for each engine to be used.

Therefore, there is a problem that it is difficult to apply it to another type of engine as it is, and it is difficult to use it as a versatile jig for various engines. In addition, in order to mount the jig, it is necessary to remove the journal cap of the camshaft, and when there are a plurality of shim replacement locations, the work of mounting the jig is complicated. Had.

Further, for example, in a vehicle equipped with an engine having a horizontally opposed cylinder or the like mounted horizontally, the space formed between the cylinder head and the side wall of the engine room is often narrow. In such a case, it is difficult to secure a work space for mounting the shim replacement jig, and even when the work space can be secured, it is difficult to visually check the jig mounting work.

Therefore, working with the engine mounted on the vehicle takes a long time and deteriorates workability. Therefore, in a vehicle equipped with the above-described engine, the engine must be removed from the vehicle to work. However, the number of work processes is greatly increased, resulting in high cost and long work time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to have versatility applicable to various engines, without removing a camshaft or a journal cap, and without removing an engine. It is an object of the present invention to provide a shim replacement jig which can be easily mounted in a state of being mounted on a vehicle, and which can surely and easily expand the space between the valve lifter and the cam.

[0016]

According to a first aspect of the present invention, there is provided a shim changing jig which intersects a reciprocating direction of a valve lifter and is orthogonal to an axis of a cam shaft. A lateral movement restraining part that suppresses lateral movement with respect to the cylinder head by expanding and contracting in the direction, and an upward movement restraining part that is interposed between the camshaft and the valve lifter and restrains upward movement with respect to the cylinder head. An arm having a base end side pivotally supported by the main body and having an engagement portion at the rotation distal end capable of engaging with the cam-facing surface; and a rotation of the arm in a valve opening direction in which the valve lifter is separated from the camshaft. A rotating means for rotating the distal end side is provided.

According to this, the shim replacement jig includes the main body,
The main body includes an arm and a rotation unit, and the main body includes a lateral movement suppression unit and an upward movement suppression unit. The lateral movement suppressing unit suppresses lateral movement with respect to the cylinder head by expanding and contracting in a direction intersecting the reciprocating movement direction of the valve lifter and orthogonal to the axis of the camshaft. In addition, the upward movement suppressing portion suppresses the upward movement of the cylinder head by projecting between the camshaft and the valve lifter and abutting on the shaft peripheral surface of the camshaft on the valve lifter side.

Thus, the main body can be fixed in a state in which the upward and lateral movement of the cylinder head is suppressed. Here, the lateral direction refers to a direction intersecting the reciprocating direction of the valve lifter and a direction orthogonal to the axial direction of the camshaft, and the vertical direction refers to a central axis direction of the bore of the cylinder.

The arm has the base end side of the arm pivotally supported by the main body, and has an engagement portion at the tip end of the rotation that abuts and engages with the cam facing surface of the valve lifter. Then, the rotating means rotates the arm so that the engaging portion moves in a valve opening direction in which the engaging portion is separated from the camshaft.

Therefore, with the main body fixed at a predetermined position of the cylinder head, the engaging portion can be easily brought into contact with and engaged with the cam facing surface of the valve lifter.

When the arm is turned by the turning means in a state where the engaging portion is engaged with the valve lifter, the turning tip side provided with the engaging portion is moved in the valve opening direction. it can.

At this time, an urging force acts on the valve lifter in the valve closing direction, and this urging force acts to move the main body upward of the cylinder head. Since it protrudes to the position between the valve lifter and suppresses the upward movement of the cylinder head, the movement in that direction is suppressed.

Therefore, with the main body fixed to the cylinder head, the valve lifter engaged with the engaging portion can be moved in the valve opening direction, and the valve lifter can be separated from the cam. Thus, a space can be formed between the valve lifter and the cam so that the shim mounted on the cam facing surface can be taken in and out.

As described above, the main body can suppress the lateral and upward movements only by expanding and contracting the lateral movement suppressing portion on the cylinder head. Therefore, it can be easily mounted on the cylinder head, and can be positioned and fixed. And, it has versatility that can correspond to various engines. Further, since the main body is easily positioned, the engagement portion can be easily engaged with the valve lifter.

According to a second aspect of the present invention, there is provided a shim replacement jig, wherein the lateral movement suppressing portion axially supports one of the camshafts arranged in a direction orthogonal to the two camshafts of the DOHC engine. A front wall facing and abutting the cam cap, a rear wall facing and abutting the cam cap supporting the other cam shaft, and a telescopic means capable of expanding and contracting a separation distance between the front wall and the rear wall. By means, the main body is fixed between the two cam caps to suppress the lateral movement with respect to the cylinder head.

According to this, the lateral movement restraining portion of the shim replacement jig fixes the main body between the two cam caps by expanding and contracting the distance between the front wall and the rear wall by the expansion and contraction means. Thereby, the main body can be fixed to the cylinder head in a state where the movement in the direction orthogonal to both the camshafts, that is, the lateral direction with respect to the cylinder head is suppressed. Further, since the distance between the front wall and the rear wall can be expanded and contracted by using the expansion and contraction means, it is possible to cope with an engine having various distances between the cam caps and to have high versatility.

According to a third aspect of the present invention, there is provided a jig for replacing a shim, wherein the lateral movement suppressing portion is arranged to extend in a direction orthogonal to two cam shafts of the DOHC engine. A front wall facing and abutting the cap, and a rear wall facing and abutting the cam cap supporting the other camshaft;
A screw mechanism having a screw body that can advance and retreat from the rear wall to the cam cap side facing the rear wall.The main body of both cam caps is formed by projecting a screw body of the screw mechanism toward the cam cap side facing the rear wall. Stretched and fixed in between to suppress lateral movement with respect to the cylinder head.

According to this, the lateral movement suppressing portion of the shim replacement jig causes the screw body of the screw mechanism to protrude from the rear wall toward the opposing cam cap so that the main body is located between the two cam caps. And fix it. This allows
The main body can be fixed to the cylinder head in a state in which the movement in the direction perpendicular to both cam shafts, that is, in the lateral direction with respect to the cylinder head is suppressed. In addition, it is possible to cope with an engine having various distances between the cam caps by adjusting the amount of protrusion of the screw body, thereby providing high versatility.

According to a fourth aspect of the present invention, there is provided a jig for replacing a shim, comprising: a cam-facing surface contact portion having an engaging portion facing the cam-facing surface; and a side wall surface contacting portion facing the side wall surface of the valve lifter. The shim replacement jig according to any one of claims 1 to 3, wherein:

According to this, when the engaging portion is engaged with the valve lifter, the cam facing surface contact portion contacts the cam facing surface, and the side wall surface contact portion faces the side wall surface of the valve lifter, or Abut By the side wall surface contact portion, the amount of protrusion of the cam facing surface contact portion on the cam facing surface is restricted to a predetermined amount or less.

Therefore, the cam-facing surface contact portion can be protruded from the cam-facing surface on the cam-facing surface by a distance that does not make contact with the shim, and can be brought into contact with the cam-facing surface. Can be combined. This allows
Shims can be easily replaced.

The jig for shim replacement according to the fifth aspect is characterized in that the engaging portion is configured to be simultaneously engageable with two valve lifters arranged side by side and reciprocally movable in the same direction. I do.

Thus, the two valve lifters, which are arranged side by side and can reciprocate in the same direction, can be simultaneously moved in the valve opening direction to form a predetermined gap with the cam.
The shims of two valve lifters can be replaced at a time.

Here, the two valve lifters which are arranged side by side and can reciprocate in the same direction are, for example, a DOHC engine having four valves for one cylinder, which is simultaneously opened and closed by one cam. A valve lifter provided for one intake valve corresponds to this.

According to a sixth aspect of the present invention, there is provided a jig for exchanging shims, wherein the arm has an elongated hole at a base end thereof, and the engaging portion of the arm is formed by a spindle provided through the elongated hole and provided on the main body. It is characterized by being axially mounted so as to be movable a predetermined distance in the extension direction.

This allows the arm to have a play that allows the engagement portion to move in the direction of coming into contact with and separating from the valve lifter. Therefore, when the main body is fixed to the cylinder head, the individual differences of the engine can be absorbed by play and the engagement portion of the arm can be reliably engaged with the valve lifter. Also, when the arm is rotated by the rotation means,
The engagement portion located on the rotation tip side can be moved substantially linearly in the reciprocating direction of the valve lifter, and the engagement state of the engagement portion with the valve lifter can be further improved.

According to a seventh aspect of the present invention, there is provided a shim replacement jig, wherein the rotating means extends from the position of the tip of the arm to rotate, the lift plate facing the upper surface of the body, and the upper surface position of the body facing the lift plate. A bolt hole drilled downward from the bottom, and a pivot bolt one end of which is screwed into the bolt hole and the other end is engageable with the lift plate. The screwing operation causes the lift plate to approach the upper surface of the main body, and rotates the arm so that the engagement portion moves in the valve opening direction in which the engagement portion is separated from the camshaft.

Accordingly, the valve lifter engaged with the engaging portion can be easily moved in the valve opening direction.
Therefore, the space between the valve lifter and the cam can be expanded, and a predetermined gap can be easily formed between the two.

[0039]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram for schematically explaining a shim replacement jig according to the first embodiment. The shim replacement jig 1 according to the present embodiment includes two valve lifters adjacent to one cylinder in a DOHC engine having four valves for one cylinder, that is, two valve lifters on either the intake side or the exhaust side. Is a jig that enables the shim mounted on the main body 2 to be replaced at a time, and includes a main body 2 and an arm 3 as illustrated.

The main body 2 has a substantially rectangular rectangular shape, and is provided with an upward movement suppressing portion 19 projecting forward at a predetermined length on the front surface. The arm 3 has a pivoting distal end projecting forward from the front of the main body 2, and a base end supported by a pivot bolt 6 at a rear position on the left and right side surfaces of the main body 2. A turning bolt 4 that passes vertically through the lift plate 40 of the arm 3 is screwed into the upper surface 11 of the main body 2. Reference numerals 7, 8 and 9 in the drawings are washers.

FIG. 2 is an explanatory view showing the mounting state where the shim replacement jig of FIG. 1 is mounted on the cylinder head 50 from the side, and FIG. 3 is an explanatory view showing the mounting state from above. is there. Hereinafter, for convenience of explanation, the left side in FIG. 2 is referred to as a front side, the right side as a rear side, the valve operating chamber side as an upper side, the combustion chamber side as a lower side, the near side as a left side, and the far side as a right side.

The cylinder head 50 for performing shim replacement using the shim replacement jig 1 opens and closes two camshafts and four valves provided for one cylinder by the cams of the camshafts. Used for DOHC 4-valve engines.

As shown in FIG. 2, the cylinder head 50 has a valve operating chamber 53 at the upper part and a combustion chamber ceiling part 52 constituting a ceiling part of the combustion chamber 51 at the lower part. Valve train 5
The cam shafts 60 and 70 extending in the left-right direction and supported in parallel at a predetermined distance in the front-rear direction are provided at the upper position in the camshaft 3, and the cam shafts 60 and 70 are cams 61 having a predetermined lift amount. , 71.

The cylinder head 50 has an intake port 54 having one end opened to the front side wall of the cylinder head 50 and the other end opened to the front side of the combustion chamber ceiling 52, and one end formed to the rear side wall of the cylinder head 50. An exhaust port 55 is provided which is open and the other is open to the rear side of the combustion chamber ceiling 52. The intake port 54 and the exhaust port 55 each have a combustion chamber side that is branched from one passage to two passages in the middle of the system path, and the combustion chamber ceiling 52 has two intake ports and two The exhaust port is open (not shown).

Openings of the intake port 54 and the exhaust port 55 on the combustion chamber ceiling 52 side are respectively provided with intake valves 62.
And an exhaust valve 72 are provided. The intake valve 62 and the exhaust valve 72 are opposed to each other at a predetermined angle so that the upper part expands. The intake valve 62 and the exhaust valve 72 are held in the combustion chamber 51 by a valve guide so as to advance and retreat. Has been energized.

The intake port 54 and the exhaust port 5
5 is seated on the valve seats 63 and 73 provided at the opening on the side of the ceiling 52 of the combustion chamber, so that the intake port 54
The exhaust port 55 is closed (hereinafter, the direction in which the valve protrudes is referred to as the valve opening direction, and the direction in which the valve is seated on the valve seat is referred to as the valve closing direction).

The valve stems of the intake valve 62 projecting upward and forward at a predetermined angle from the floor of the valve operating chamber 53 and the valve stem of the exhaust valve 72 projecting upward and rearward at a predetermined angle are provided on the respective top surfaces of the valve lifters 64 and 74. Are placed in a state of being covered.

The valve lifters 64 and 74 have a cylindrical shape with their upper ends closed, and are inserted into valve lifter guides 56 and 57 formed in the valve operating chamber 53 to advance and retreat the intake valve 62 and the exhaust valve 72, respectively. It is guided so as to be able to reciprocate in the same direction.

Cam facing surface 6 of valve lifters 64 and 74
5 and 75 are provided with recesses 66 and 76 formed in a substantially disc-shaped recess at the center thereof, leaving outer edges 65a and 75a of a predetermined width, and shims 67 for adjusting valve clearance.
77 is exchangeably mounted. Shims 67 and 77
When mounted in the recesses 66, 76, the upper surface thereof
It has a substantially disk shape having a thickness that protrudes higher toward the cams 61 and 71 than a and 75a.

Cams 61 and 71 are arranged at positions facing the cam facing surfaces 65 and 75, and the cam shafts 60 and 70 are rotated in conjunction with a crankshaft (not shown) so that the cams 61 and 71 are rotated. 71 is in sliding contact with shims 67, 77 mounted on the cam facing surfaces 65, 75, and the valve lifters 64, 74
Is reciprocated in the forward and backward directions of the intake valve 62 and the exhaust valve 72.

The shims 67 and 77 have a role of adjusting the positions of the valve lifters 64 and 74 with respect to the cams 61 and 71. When the cam facing surfaces 65 and 75 face the base circles of the cams 61 and 71, The thickness is set such that the intake valve 62 and the exhaust valve 72 are seated on the valve seats 63 and 73. Therefore, the shims 67 and 77 and the cams 61 and 71 are always in contact with each other or face each other with a slight valve clearance (in the figure, the shim 77 is used).
And the state of the cam 71).

Next, the cylinder head 5 having the above configuration will be described.
The individual components of the shim replacement jig 1 attached to the jig 0 will be described below with reference to FIGS. 4A and 4B are explanatory views showing the configuration of the main body 2, wherein FIG. 4A is a top view, and FIG. 4B is a side view of FIG. The main body 2 includes a fixed block 10 and a slider block 20.

As shown in FIG. 4, the fixed block portion 10 includes an upper surface portion 11 and a lower surface portion 12 having a substantially planar shape, a front wall portion 13, a side wall portion 14 having a substantially vertical planar shape, and a rear position. And a slide wall 15 having an inclined surface inclined toward the upper surface at a predetermined angle.

The upper surface 11 is provided with a bolt hole 16 which is bored vertically from the upper surface 11 and into which the rotating bolt 4 can be screwed. The bolt hole 16 is formed at the center of the upper surface 11 in the left-right direction and at a position closer to the front wall 13. The lower surface portion 12 is longer than the upper surface portion 11 by a predetermined length, and is formed in a substantially planar shape that can be placed on the upper surface 50a of the cylinder head 50.

The front wall portion 13 has a planar shape extending in the vertical direction, and has an area capable of contacting the cam cap on the side that pushes down the valve lifter. On the side wall portion 14,
There is provided a bolt hole 17 for a shaft bolt which is bored in a horizontal direction through the space between the left and right side wall portions 14a and 14b at a position on the lower surface portion 12 side and near the slide wall portion 15 side,
A shaft bolt 6 having a predetermined diameter and rotatably supporting the arm 3 can be screwed therein.

The slide surface portion 15 has a slide hanging surface 15a that hangs downward from the rear end of the upper surface portion 11 at a predetermined height.
A sliding flat surface 15b extending rearward in the horizontal direction by a predetermined distance from the lower end of the slide hanging lower surface 15a, and a substantially inclined surface inclined at a predetermined angle gradually approaching the lower surface portion 12 as it moves rearward from the rear end of the sliding flat surface 15b. And a slide inclined surface 15c having a planar shape.

When viewed from the top, the slide hanging surface 15a has a substantially U-shape in which the left and right central portions are concave forward (see FIG. 7A). It is provided so as to be located at a height of about two thirds of the height of the main body 2 (see (B) in the figure).

A bolt hole 18 for a fixing bolt is formed at the center of the boundary between the slide flat surface 15b and the slide inclined surface 15c. Bolt hole for fixing bolt 1
As shown in FIG. 4B, 8 is formed so as to extend in the vertical direction at a position rearward from the bolt hole 17 for the support bolt, and the slider block 20 is attached to the fixed block 10. On the other hand, it has a diameter capable of screwing a fixing bolt (see FIG. 1) 5 for fixing it at a predetermined position.

The left and right ends of the front wall portion 13 are provided with upward movement suppressing portions 19 projecting forward by a predetermined length. The upward movement suppressing portion 19 has a substantially triangular plate shape having a predetermined thickness in the left-right direction and an acute angle portion at a front end, and the front end extends obliquely downward and forward with respect to the front wall portion 13. I have.

When mounted on the cylinder head 50, the upward movement restraining portion 19 has a length and a shape whose tip is located between the camshaft and the valve lifter. 19d, there is a gap that allows one of the cam caps to be interposed when fixed to the cylinder head 50. In addition, the outer wall surface 19
a, 19b are formed so as to be flush with the left and right side wall portions 14a, 14b.

The lower surface 19f of the upward movement suppressing portion 19 has an angle substantially perpendicular to the reciprocating direction of the valve lifter after hanging downward from the front portion of the lower surface portion 12 by a predetermined length.
e extends at an angle crossing the lower surface 19f at a position separated by a predetermined distance forward from the lower position of the front wall portion 13, and forms an acute angle portion with the upper surface 19e and the lower surface 19f.

The slider block portion 20 has an upper surface portion 21 and a lower surface portion 22 having a substantially planar shape, a slider surface portion 23 having an inclined surface inclined downward at a predetermined angle at a front position, and a substantially vertical planar shape. It has a side wall portion 24 and a rear wall portion 25, and the height between the upper surface portion 21 and the lower surface portion 22 is set lower than the height between the upper surface portion 11 and the lower surface portion 12 of the fixed block portion 10. .

The upper surface portion 21 is provided with an elongated hole 26 having a predetermined length in the front-rear direction, penetrating vertically to the lower surface portion 22 at a substantially central position thereof. The elongated hole 26 has a diameter through which the fixing bolt 5 can be inserted. The lower surface 22 is formed shorter than the upper surface 21.

The rear wall portion 25 has a planar shape extending in the vertical direction, and has an area capable of abutting against a cam cap for supporting the other cam shaft disposed opposite to the cam cap for pushing down the valve lifter. are doing.

Further, ribs 27a and 27b projecting rearward at a predetermined height from the upper surface 21 to the lower surface 22 are provided at both left and right end portions of the rear wall portion 25, respectively. The cam cap 81 is set to be inserted between the ribs 27a and 27b (see FIG. 3). The side wall portion 24 is formed so as to be flush with the side wall portions 14a and 14b when being combined with the fixed block portion 10.

The slider surface portion 23 has a slider hanging surface 23a hanging downward by a predetermined distance from the front end, a slider ceiling surface 23b extending horizontally rearward from the lower end of the slider hanging surface 23a by a predetermined distance, and a slider ceiling surface 23b. A slider inclined surface 23c of a substantially planar shape gradually approaching the lower surface portion 22 as it moves rearward from the end and is inclined obliquely downward and rearward at a predetermined angle.

The slider hanging surface 23a has a central portion projecting forward by a predetermined length when viewed from the upper surface (see FIG. 7A), and the slider block portion 20 is appropriately assembled to the fixed block portion 10. In this case, it is formed in a shape that always engages with the slide hanging surface 15a. This allows
The slider block 20 is prevented from rotating around the fixing bolt 5.

Further, the height distance of the slider hanging surface 23a is shorter than the height distance of the sliding hanging surface 15a of the fixed block portion 10. In this embodiment, the sliding hanging surface 1
5a is formed to have a height distance of about half or less. The slider ceiling surface 23b always faces the slide flat surface 15b, and is formed to be shorter in the front-rear direction than the slide flat surface 15b.

The slider inclined surface 23c is formed so as to form an angle facing the slide inclined surface 15c, and is in surface contact with each other. Therefore, the slider block 2
In the case of 0, the slider inclined surface 23c moves on the slide inclined surface 15c, whereby the position of the rear wall portion 25 can be changed in the front-rear direction with respect to the main body block portion 10 while maintaining the vertical state.

Therefore, when the fixing bolt 5 is tightened in a state where the fixed block portion 10 and the slider block portion 20 are united, the slider block portion 20 moves rearward with respect to the fixed block portion 10 and moves in the front-rear direction of the main body 2. Length can be extended. When the fixing bolt 5 is loosened, the slider block 20 slides on the slide inclined surface 15c and moves forward, so that the length of the main body 2 in the front-rear direction can be reduced.

Thus, when the shim replacement jig 1 is placed between the cam caps and the fixing bolts 5 are tightened, the main body 2 extends in the front-rear direction and is fixed between the cam caps 80 and 81 by tension ( (See FIG. 2). Therefore, the movement of the main body 2 in the front-rear direction can be suppressed.

The inner side wall 1 of the upward movement suppressing portion 19
9c and 19d face the left and right side surfaces of the cam cap 80,
The ribs 27a and 27b of the slider block 20 face the left and right sides of the cam cap 81 (see FIG. 3). Therefore, the movement of the main body 2 in the left-right direction can also be suppressed.

FIGS. 5A and 5B are explanatory views showing the structure of the arm 3, wherein FIG. 5A is a top view and FIG.
FIG. The arm 3 includes an arm plate 30
And a lift plate 40.

The arm 3 is connected to the left and right side wall portions 14 of the main body 2.
The arm plate 30 includes an arm plate 30 that is disposed to face each of the a and b, and a lift plate 40 that faces the upper surface 11 of the main body 2 and connects the left and right arm plates 30.

The arm plate 30 has a plate shape having a predetermined thickness approximating a shape obtained by turning a substantially T-shape laterally, as shown in B in the figure, and extends vertically by a predetermined length. It has a vertical arm plate 31 and a horizontal arm plate 32 extending rearward from a substantially central position of the vertical arm plate 31.

The upper portion of the vertical arm plate 31 is formed to be longer than the lower portion by a predetermined length in the front-rear direction, that is, wide. The upper end of the vertical arm plate 31 is connected to the upper end of the other vertical arm plate 31 via the lift plate 40. Arm plate 30
When viewed from the front side, it has a substantially U-shaped shape whose upper part is closed (not shown).

The lower end of the vertical arm plate 31 is formed so as to be bent forward at a predetermined angle as shown in FIG. 2B, and its front end face 34 has a substantially planar shape. The front end surface 34 has an inclination angle in the vertical direction that extends substantially in the same direction as the reciprocating direction of the valve lifter, as shown in (B) in the figure, and also as shown in (A) in the figure. In addition, it has an angle that gradually widens from the inside to the outside in the left-right direction as it moves from the front to the rear. The angle of the front end face 34 in the left-right direction is formed so as to be perpendicular to the radial direction of the valve lifter to be engaged.

An engaging portion 33 engageable with the valve lifter is formed at the lower end of the front end surface 34. The engagement portion 33 includes a lifter facing surface 35 that faces and contacts the cam facing surface of the valve lifter, and a side wall face facing surface 36 that faces and contacts the sidewall surface of the valve lifter.

The side wall surface facing surface 36 is provided with a plane parallel to the front end surface 34 at a position shifted from the front end surface 34 by a predetermined distance to the base end side. Can face and abut. The lifter facing surface 35 extends from the upper end of the side wall surface facing surface 36 perpendicularly to the front end surface 34 by a predetermined distance, and
When it is engaged with the cam 4, it comes into contact with the cam facing surfaces 65 and 75.

The horizontal arm plate 32 has substantially the same thickness as the vertical arm plate 31, and has a long hole extending in the longitudinal direction of the horizontal arm plate 32 and extending in the left-right direction at the base end side extending rearward. 37.

The elongated hole 37 has an inside diameter that allows the shaft bolt 6 to be screwed into the shaft bolt bolt hole 17 provided in the side wall portion 14 of the main body 2. By supporting the arm 3 with the support bolt 6, the engagement portion 33 is formed into the elongated hole 3.
7 can be moved in the major axis direction.

The lift plate 40 includes the arm plate 3
0, and the length in the left-right direction is equal to the body 2 between the arm plates 30 connected to the left and right ends and facing each other.
And a length in the left-right direction that can form a predetermined gap between the inner side surface of the arm plate 30 and the side wall portion 14 of the main body 2.

A notch 41 is formed at a central position in the left-right direction of the lift plate 40 with a predetermined length and a predetermined width from the rear end side toward the front. Notch 41
Has a substantially U-shape when viewed from above ((A) in the figure).
), When the arm 3 is assembled to the main body 2,
(Refer to FIG. 3).

The length of the notch 41 in the front-rear direction is determined when the arm 3 is rotatably assembled to the main body 2 with the support bolt 6 so that the lift plate 40 and the upper surface 11 of the main body 2 face each other in parallel. Bolt hole 1 from the rear end of lift plate 40
6 has a length that is cut out to a position slightly forward of a position opposite to the position 6. The left and right width of the notch 41 has a length slightly larger than the diameter of the bolt hole 16.

As shown in FIG. 1, the rotating bolt 4 has a bolt head 4a having a predetermined size, and a tip thereof is screwed into the bolt hole 16 through the notch 41 of the arm 3. The bolt head 4 above the lift plate 40
a has a length that is spaced apart.

Accordingly, the bolt head 4 a is moved by the lifting plate 40 by the screwing operation of the rotating bolt 4 into the main body 2.
Is moved in a direction to approach the upper surface portion 11 of the main body 2.
Accordingly, the arm 3 rotates downward about the elongated hole 37 as a rotation center. When the turning bolt 4 is turned in a direction to separate the bolt head 4a from the main body 2, the arm 3
Can be turned upward around the elongated hole 37.

Next, a shim replacement jig 1 having the above configuration
A method of replacing the shim 67 on the side of the intake valve 62 of the cylinder head 50 using the above will be described below. First
The operation of attaching the shim replacement jig 1 to the cylinder head 50 will be described as a step.

First, it is assumed that the assembled state shown in FIG. 1 is initially set as an initial state before the shim replacement jig 1 is attached. Here, the rotating bolt 4 is
The bolt head 4a is screwed into the bolt hole 16 so as to be located at a high position spaced above the upper surface portion 11 of the main body 2,
A state in which the distal end side of the arm 3 is engaged with the notch 41 so as to be rotatable upward is defined as an initial state.

The fixing bolt 5 has its tip end threaded into the fixing bolt bolt hole 18 through the elongated hole 26 from the upper surface 21 side of the slider block 20, and the slider block 20 is fixed to the fixing block. A state in which it is held movably up and down with respect to 10 is an initial state.

As shown in FIGS. 2 and 3, the shim replacement jig 1 set in such an initial state is
It is placed on the head upper surface 50a between the cam caps 80 and 81 supporting the 70. At this time, the front side of the shim replacement jig 1 is positioned on the intake valve 62 side (front side) for performing shim replacement, and the tip of the upward movement suppressing portion 19 is positioned between the cam shaft 60 and the valve lifter 64. As a result, the front wall portion 13 of the shim changing jig 1 is
And the rear wall portion 25 is a front side surface 8 of the cam cap 81.
1a (see FIG. 3).

Then, after the distal end side of the arm 2 is lifted upward and the engagement portion 33 is lifted above the valve lifter 64, the fixing bolt 5 whose distal end is screwed into the bolt hole 18 for the fixing bolt is screwed in. I do. As a result, the slider block portion 20 is made to approach the fixed block portion 10 in the vertical direction, moves downward on the slide inclined surface 15c in contact with the slider inclined surface 23c, and gradually moves rearward.

As a result, the front wall portion 13 of the fixed block portion 10 comes into contact with the rear side surface 80a of the cam cap 80, and the rear wall portion 25 of the slider block portion 20 comes into contact with the cam cap 8
When the fixing bolt 5 is kept in contact with the front side surface 81a and the screwing operation of the fixing bolt 5 is continued, the main body 2 is fixed between the cam caps 80 and 81 in the front-rear direction. Movement to is suppressed.

In this state, the inner side walls 19c and 19d of the upward movement suppressing portion 19 face the left and right side surfaces of the cam cap 80, and the ribs 27a and 27
b faces the left and right side surfaces of the cam cap 81 (FIG. 3)
Reference), the movement of the shim replacement jig 1 in the left-right direction can also be suppressed.

As described above, the shim replacement jig 1 is easily fixed to the cylinder head 50 by merely placing it at the predetermined position on the cylinder head 50 and simply screwing the fixing bolt 5 in the front-back and left-right directions. , That is, the movement in the lateral direction can be suppressed. Also, the cam cap 8
It can be easily fixed to engines having different distances between 0 and 81, and has high versatility.

Next, as a second stage, the engaging portion 3 of the arm 3
3 and the valve lifter 64 are engaged. Specifically, the pivoting tip side of the arm 3 is lifted upward, the engaging portion 33 is lowered from the cam facing surface 65 side to the valve lifter 64, and the lifter facing surface 35 of the engaging portion 33 is brought into contact with the outer edge portion 65a. The outer peripheral wall facing surface 36 is made to face or contact the outer peripheral wall surface 65b of the valve lifter 64.

Here, the engagement portion 3 depends on the length of the arm 3.
Since the position of 3 is substantially determined, by fixing the main body 2 to a predetermined position of the cylinder head 50, the engaging portion 33 can be easily engaged with the outer edge 65a of the valve lifter 64.

The outer peripheral wall facing surface 36 abuts against the outer peripheral wall 65b of the valve lifter 64, thereby regulating the length of the front end surface 34 of the arm 3 projecting above the cam facing surface 65 of the valve lifter 64, and engaging. The part 33 is prevented from coming into contact with the shim 67. Thereby, replacement of the shim 67 can be facilitated.

The arm 3 is supported by a long hole 37 extending in the front-rear direction.
The position of the engaging portion 33 with respect to 4 can be appropriately adjusted in the front-rear direction. As a result, it is possible to reliably engage the engaging portion 33 with the valve lifter 64 by absorbing a manufacturing error or the like of the engine.

Since the outer peripheral wall facing surface 36 of the engaging portion 33 has the same angle as the front end surface 34 and is formed in a plane shape perpendicular to the radial direction of the valve lifter to be engaged, The outer peripheral wall surfaces of the valve lifters having different sizes in the radial direction can also be opposed and abutted in the perpendicular direction. Therefore, one arm 2 can cope with various engines, and high versatility can be provided.

Further, since the arm 2 is supported only by two support bolts 6, if one arm 2 cannot be used, it can be easily replaced with an arm having an engaging portion 33 corresponding to the valve position. can do.

Next, as a third step, the valve lifter 64 is moved in the valve opening direction, and the valve lifter 64 and the cam 61 are moved.
An operation for forming a gap space in which the shim 67 can be exchanged between them will be described. With the engagement portion 33 and the valve lifter 64 engaged, an operation of screwing the rotation bolt 4 into the main body 2 is performed.

Thus, the bolt head 4a moves the lift plate 40 in a direction to approach the upper surface portion 11 of the main body 2, the arm 3 moves the engaging portion 33 in the valve opening direction, and the valve lifter 64 opens the valve. Moved in the direction.

At this time, the valve 62 is attached to the valve lifter 64.
Is acting in the valve closing direction.
A force acts to move the main body 2, which is stretched and fixed between the cam caps 80 and 81 and restrained from moving in the front-back and left-right directions, upward.

However, between the cam shaft 61 and the valve lifter 64, the upward movement suppressing portion 19 protruding from the main body 2 is provided.
, The upper surface 19 of the upward movement suppressing portion 19
Since e contacts the shaft peripheral surface of the cam shaft 61 on the side facing the valve lifter 64, the upward movement of the main body 2 can be suppressed.

Therefore, the movement of the main body 2 in the front-rear, left-right and up-down directions can be completely suppressed, and the valve lifter 64 can be reliably moved in the valve opening direction, which is the lower side in the reciprocating direction.

As a result, the engagement portion 33 and the valve lifter 64
Only by the operation of tightening the turning bolt 4 in the state in which the valve lifter 64 is engaged, the valve lifter 64 can be separated from the cam 61, and a gap space in which the shim 67 can be exchanged can be reliably formed therebetween.

Further, as shown in FIG. 2, the shim replacement jig 1 according to the present embodiment can reduce the protruding height of the cylinder head 50 above. Is mounted on the vehicle, etc., and the side wall of the engine room exists above the cylinder head 50,
Even when it is difficult to secure a sufficient work space, the work can be easily attached, and the work of expanding the gap space between the valve lifter 64 and the cam 61 can be performed.

FIG. 6 is an explanatory view showing a mounting state in which the shim replacement jig according to the second embodiment is mounted on a cylinder head from the side. What is characteristic in the present embodiment is a fixing means for suppressing the movement of the shim replacement jig in the front-rear direction. The configuration will be described below.
The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The main body 90 of the shim replacement jig 1 includes an upper surface portion 91 and a lower surface portion 92 having a substantially planar shape, and a front wall portion 93, a side wall portion 94, and a rear wall portion 95 having a substantially vertical planar shape. And is formed in a rectangular parallelepiped.

A recess 9 having a substantially V-shaped groove extending between the side wall portions 94 is provided substantially at the center of the upper surface portion 91 in the front-rear direction.
6 are provided. At the rear end of the lower surface portion 92, an inclined surface portion 97 facing diagonally rearward is provided so as to be substantially parallel to the rear flat surface portion 96a of the concave portion 96.

The rear flat portion 96a and the inclined surface 97
At the substantially central position in the left-right direction, the recess 96
A bolt hole 99 into which a fixing bolt 98 can be screwed is formed from the side. The fixing bolt 98 has a length that can be screwed into the recess 96 and protrude rearward from the rear wall 95. The tip 98a of the fixing bolt 98 is formed in a substantially hemispherical shape.

Next, a shim replacement jig 1 having the above-described structure is provided.
The method for attaching the cylinder to the cylinder head 50 will be described. As shown in FIG. 6, the shim replacement jig 1 has a front wall portion 93 between the cam caps 80 and 81 and a valve lifter side for performing shim replacement, that is, a rear side surface 80a of the cam cap 80 in the present embodiment. It is placed on the upper surface 50a of the cylinder head 50 so as to face the same.

Then, by fastening the fixing bolt 98, the tip 98 a of the fixing bolt 98 is projected obliquely rearward from the inclined surface 97 to the rear wall 95, and is brought into contact with the front side surface 81 a of the cam cap 81.

Here, the distal end 98a of the fixing bolt 98 has a substantially hemispherical shape and projects obliquely rearward, so that a downward force and a rearward pressing force are simultaneously applied to the front side surface 81a.

Accordingly, the main body 90 is fixed between the cam caps 80 and 81 in the front-rear direction with a force directed to bring the lower surface portion 92 into contact with the upper surface 50a of the cylinder head 50. Thus, the shim replacement jig 1 can be prevented from moving in the front-rear direction and can be fixed, and at the same time, the upward movement of the main body 90 can be suppressed.

Further, as compared with the first embodiment, the number of parts constituting the main body 90 can be reduced, and the manufacturing cost can be reduced. Further, there is an effect that the fixing operation can be further facilitated because the number of movable parts is small.

The operation for separating the valve lifter 64 and the cam 61 using the shim replacement jig 1 in the present embodiment and the operation and effect thereof are the same as those in the first embodiment, and a description thereof will be omitted.

The shim replacement jig according to the present invention is not limited to the above embodiments, and various modifications can be made within the gist of the present invention. For example, as the turning means of the arm 3, the turning bolt 4 is used in each of the above-described embodiments. However, the present invention is not limited to this, and has the same function as the turning bolt 4, that is, Any mechanism that allows the lift plate 40 of the arm 3 to approach the upper surface 11 of the main body 2 may be used. For example, a cam mechanism having a predetermined lift amount may be used.

[0120]

As described above, according to the shim replacement jig according to the present invention, it is possible to easily fix the jig in a state where the movement of the main body with respect to the cylinder head in the front-rear, left-right and up-down directions is completely suppressed. it can. Further, the engagement portion can be easily engaged with the valve lifter by fixing the main body.
Accordingly, the valve lifter and the cam can be separated from each other, and a gap space in which the shim can be exchanged can be easily and reliably formed therebetween.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram showing a first embodiment.

FIG. 2 is an explanatory view showing a mounting state in which the shim replacement jig of FIG. 1 is mounted on a cylinder head from a side.

FIG. 3 is an explanatory view showing the mounting state shown in FIG. 2 from above.

FIG. 4 is an explanatory view of a main body.

FIG. 5 is an explanatory diagram of an arm.

FIG. 6 is an explanatory diagram showing a mounting state in which the shim replacement jig according to the second embodiment is mounted on a cylinder head, as viewed from the side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shim replacement jig 2 Main body (1st Embodiment) 3 Arm 4 Rotating bolt (rotating means) 10 Fixed block part (lateral movement suppression part) 19 Upward movement suppression part 20 Slider block part (horizontal) 33 direction engaging portion 50 cylinder head 51 combustion chamber 53 valve operating chamber 60 camshaft 61 cam 62 intake valve 64 valve lifter 65 cam facing surface 67 shim 72 exhaust valve 74 valve lifter 98 fixing bolt (screw body)

Claims (7)

[Claims] 1. A camshaft provided with a cam having a predetermined lift amount and rotatably supported at an upper position of a valve operating chamber of a cylinder head having a valve operating chamber at an upper part and a combustion chamber at a lower part, and a lower position of the cam shaft. A valve provided so as to be able to open and close the valve by moving into and out of the combustion chamber, the top of the head being urged in a valve closing direction to approach the cam; and An engine having a direct-acting type valve actuating mechanism having a valve lifter guided reciprocally and having a cam facing surface facing a cam, and a shim mounted on the cam facing surface of the valve lifter and in sliding contact with the cam. A shim replacement jig for replacing the shim, wherein the jig is expanded and contracted in a direction intersecting the reciprocating movement direction of the valve lifter and orthogonal to the axial direction of the camshaft, thereby causing a lateral movement with respect to the cylinder head. A main body having a lateral movement suppressing portion for suppressing the movement of the cylinder head, and an upward movement suppressing portion interposed between the camshaft and the valve lifter for suppressing the upward movement of the cylinder head. An arm having a base end that is pivotally supported, and an engagement portion at the rotation tip end that abuts and engages the cam facing surface; and an arm that moves in the valve opening direction in which the engagement portion is separated from the camshaft. And a turning means for turning the jig. 2. A front wall which opposes and abuts a cam cap which rotatably supports one of the camshafts arranged in a direction orthogonal to the two camshafts of the DOHC engine. A back wall that faces and abuts a cam cap that supports the other cam shaft; and a telescopic unit that can expand and contract the distance between the front wall and the rear wall. The jig according to claim 1, wherein the jig is fixed between the caps to suppress the lateral movement with respect to the cylinder head. 3. The DOHC engine further comprises: a front wall that faces and abuts a cam cap that supports one of the camshafts disposed in a direction orthogonal to the two camshafts of the DOHC engine. A back wall facing and abutting a cam cap that supports the other cam shaft, and a screw mechanism having a screw body that can advance and retreat from the back wall toward the facing cam cap. By projecting a body toward the cam cap facing the back wall, the main body is stretched and fixed between the two cam caps, thereby suppressing lateral movement with respect to the cylinder head. Item 2. A shim replacement jig according to Item 1. 4. The device according to claim 1, wherein the engaging portion includes a cam facing surface contact portion facing the cam facing surface, and a side wall surface contact portion facing the sidewall surface of the valve lifter. Item 4. A shim replacement jig according to any one of Items 1 to 3. 5. The device according to claim 1, wherein the engagement portion is configured to be simultaneously engageable with two valve lifters arranged side by side and reciprocally movable in the same direction. The described shim replacement jig. 6. The arm has an elongated hole at a base end of the arm, and the engaging portion is fixed in a direction in which the arm extends by a support shaft penetrating the elongated hole and provided on the main body. The jig for shim exchange according to any one of claims 1 to 5, wherein the jig is mounted so as to be movable by a distance. 7. A lift plate extending from a position of the arm at a tip end of rotation and facing a top surface of the main body, and a punching plate downwardly from a top surface position of the main body facing the lift plate. Provided with a bolt hole, one end of which is screwed into the bolt hole, and the other end of which is a turning bolt which can be engaged with the lift plate. The lift plate is moved closer to the upper surface of the main body, and the arm is rotated so that the engagement portion moves in a valve opening direction in which the engagement portion is separated from the cam shaft.
The jig for exchanging shims according to any one of claims 1 to 6.