Rocker arm gripping jig

Abstract

To provide a rocker arm gripping jig that can grip a rocker arm even in a small space or can perform releasing thereof.SOLUTION: A rocker arm gripping jig 1 for gripping a rocker arm 30 includes a first gripping part 12 and a second gripping part 13 respectively abutting on two parts on one side and the other side of an outer peripheral surface of a roller 32 provided in the rocker arm 30.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a rocker arm gripping jig. [Background technology]

[0002] Rocker arms are attached to the cylinder head as part of the valve train that opens and closes the engine valves. To reduce friction, roller rocker arms, which have cylindrical rollers inside the case, are often used for these rocker arms.

[0003] As a method for assembling a rocker arm, for example, Patent Document 1 discloses a method in which a rocker arm is placed on top of a valve assembled to a cylinder head, and then a camshaft is assembled to the cylinder head while holding down multiple rocker arms with an assembly jig.

[0004] When mounting a rocker arm on a cylinder head, the rocker arm can be gripped with a jig and placed on top of a valve. In the case of roller-type rocker arms, a conventional method for gripping the rocker arm involves bringing a pair of openable grippers into contact with relatively flat portions on both sides of the rocker arm (for example, both axial ends of the cylindrical roller shaft) from the outside. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-159032 Summary of the Invention [Problem to be solved by the invention]

[0006] Depending on the configuration of the cylinder head, the distance between both sides of the rocker arm case and the wall of the cylinder head may be so short that there is no space to insert the gripping part that grips the rocker arm or to open and close the gripping part to grip or release the rocker arm. This makes it difficult to grip the rocker arm and assemble it to the cylinder head using conventional methods.

[0007] An object of the present invention is to provide a rocker arm gripping jig that can grip or release a rocker arm even in a small space. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a rocker arm gripping jig for gripping a roller rocker arm, the rocker arm gripping jig comprising a first gripping portion and a second gripping portion that respectively contact two locations on one side and the other side of the outer peripheral surface of a roller provided in the roller rocker arm. The first gripping portion and the second gripping portion have a variable distance therebetween and include a flat portion. It is characterized by:

[0009] The gripping jig of the present invention grips the rocker arm not on the flat portion of the rocker arm, but by abutting the gripping parts at two points on the outer circumferential surface of the roller, which is a curved portion. Therefore, even if there is no space between the cylinder head and the side of the rocker arm to be assembled, for example, the rocker arm can be inserted into the cylinder head to assemble it, or the gripped state can be released inside the cylinder head and the rocker arm gripping jig can be retracted from the cylinder head.

[0010] The rocker arm gripping jig further includes a biasing member that biases the second gripping portion toward the first gripping portion, and the distance between the tip of the first gripping portion and the tip of the second gripping portion can be made smaller than the diameter of the roller. This allows the second gripping portion to be pushed apart along the outer peripheral surface of the roller against the biasing force of the biasing member during the process of inserting the first gripping portion and the second gripping portion into the gap in the rocker arm and bringing them into contact with the outer peripheral surface of the roller. Therefore, the first gripping portion and the second gripping portion can apply a gripping force to the roller without requiring any special operation.

[0011] In the rocker arm gripping jig, the first gripping portion and the second gripping portion can be configured as flat plates. This minimizes the space required to insert the first gripping portion and the second gripping portion into the gap in the rocker arm or to retract them from the gap. Therefore, even if there is limited space outside the outer circumferential surface of the roller of the rocker arm, the rocker arm can be gripped and released. [Effects of the Invention]

[0012] According to the rocker arm gripping jig of the present invention, the rocker arm can be gripped by gripping the outer peripheral surface of the roller, and the rocker arm can be gripped or released even in a small space. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a front view of a rocker arm assembly jig according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the rocker arm assembly jig. [Figure 3] FIG. 2 is a perspective view of a rocker arm assembly jig. [Figure 4] FIG. 2 is a side view of the rocker arm assembly jig. [Figure 5] FIG. [Figure 6] FIG. 2 is a plan view of the rocker arm. [Figure 7]2 is a cross-sectional view taken along line EE in FIG. 1 showing the state before the rocker arm assembly jig grips the rocker arm. FIG. [Figure 8] 10 is a cross-sectional view showing the state before the rocker arm assembly jig grips the rocker arm. FIG. [Figure 9] 4 is a cross-sectional view showing the rocker arm assembly jig gripping the rocker arm. FIG. [Figure 10] 10 is a cross-sectional view showing the rocker arm assembly jig releasing its grip on the rocker arm. FIG. [Figure 11] 10A and 10B are diagrams illustrating how the rocker arm is assembled to the cylinder head. [Figure 12] FIG. 2 is a diagram showing a state in which the rocker arm is assembled to the cylinder head. [Figure 13] FIG. 10 is a cross-sectional view of a state in which the gripping side is reversed from that of FIG. 9. [Figure 14] 13 is a cross-sectional view showing the state in which the rocker arm assembly jig releases the grip on the rocker arm in the case of FIG. 12. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described below with reference to the drawings. A rocker arm gripping jig according to an embodiment of the present invention is a jig for assembling a roller rocker arm equipped with a roller to a cylinder head. Hereinafter, this roller rocker arm will be simply referred to as a rocker arm, and the jig used for assembling will be referred to as a rocker arm assembly jig.

[0015] FIG. 1 is a front view of a rocker arm assembly jig according to one embodiment of the present invention, FIG. 2 is a plan view, and FIG. 3 is a perspective view. As shown in Figures 1 to 3, rocker arm assembly jig 1, which serves as a rocker arm gripping jig, comprises a pair of gripping levers 2, a pair of operating levers 3, multiple support portions 4, a connecting portion 5, a positioning portion 6, a gripping portion 7, etc. In the following explanation, the downward direction in Figure 1 refers to the rocker arm side that is gripped as the downward direction of rocker arm assembly jig 1, and the opposite direction as the upward direction. Furthermore, the direction perpendicular to this up-down direction, in which multiple support portions 4 are arranged side by side (or the extending direction of gripping levers 2, which is the left-right direction in Figure 1), is referred to as the left-right direction of rocker arm assembly jig 1.

[0016] The rocker arm assembly jig 1 of this embodiment has three support parts 4. The support parts 4 support mechanisms such as a gripping lever 2, a gripping part 7, and an operating lever 3 for opening and closing the gripping part 7 (described in detail later). The support parts 4 are connected by a rod-shaped connecting part 5. The cylinder head that the rocker arm assembly jig of this embodiment is compatible with has four valves arranged around the spark plug holes of each of the in-line three-cylinder cylinders. One rocker arm is arranged corresponding to each valve. Each support part 4 has a gripping part 7. Each gripping part 7 can grip one rocker arm 30. In other words, the rocker arm assembly jig 1 of this embodiment can grip three rocker arms 30 at the same time and assemble them to the cylinder head.

[0017] The support parts 4 at both ends are provided with gripping levers 2 at their tops. The gripping levers 2 can be extended and retracted in the left-right direction in Figure 1, and can be retracted when storing the rocker arm assembly jig 1, and extended when in use.

[0018] A positioning portion 6 is provided on the central support portion 4. A positioning through hole 6a (see FIG. 2) is provided on the inside of the positioning portion 6. The rocker arm assembly jig 1 can be positioned at a predetermined position by inserting a positioning pin provided on a positioning jig or the like into the through hole 6a of the positioning portion 6. This allows the rocker arm assembly jig 1 to be positioned at a predetermined position relative to the rocker arm 30, cylinder head, etc., for example, when the rocker arm assembly jig 1 grips the rocker arm 30 or when the gripped rocker arm 30 is placed on a cylinder head.

[0019] As shown in Fig. 3, the central support part 4 is provided with a pair of link members 11 that are rotatable relative to the support part 4. One end 11a of the link members 11 is fixed to the central support part 4, and the link members 11 rotate around the one end 11a relative to the support part 4. The other end 11b of the link members 11 is connected to the operating lever 3.

[0020] As shown in FIG. 4, the gripping portion 7 is made up of a first gripping portion 12 and a second gripping portion 13. The first gripping portion 12 and the second gripping portion 13 are flat plates. The first gripping portion 12 and the second gripping portion 13 are made of a material that is softer than the roller 32 (see FIG. 5), which will be described later. This prevents the first gripping portion 12 and the second gripping portion 13 from damaging the surface of the roller 32 when they come into contact with the roller 32. As an example, in this embodiment, the first gripping portion 12 and the second gripping portion 13 are made of stainless steel.

[0021] One end of each first gripping portion 12 is fixed to the corresponding support portion 4, and the other end extends vertically downward along the support portion 4.

[0022] One end of each second gripping portion 13 is fixed to the operating lever 3, and the other end abuts against a guide surface 14a of the guide portion 14. The guide surface 14a is an inclined surface that slopes downward toward the support portion 4.

[0023] The guide part 14 is attached to the support part 4 via a retaining member 16. The retaining member 16 is inserted into the support part 4 through a through-hole 13a provided in the second grip part 13 (see FIG. 7). As shown in FIG. 4, the guide part 14 is biased to the left side of the drawing relative to the support part 4 by a spring 15 serving as a biasing member provided in the retaining member 16.

[0024] The other end of second gripping portion 13 is guided by guide surface 14a and tilted toward support portion 4. In this way, one end of second gripping portion 13 is fixed to operating lever 3 and the other end is guided toward support portion 4, so that second gripping portion 13 is positioned tilted with respect to the vertical direction in Fig. 4. Due to this tilt, when operating lever 3 is in a free state where no operating force is being applied, first gripping portion 12 and second gripping portion 13 form a roughly V-shape.

[0025] 4. The second gripping portion 13 is in contact with a plunger 17 fixed to the support portion 4 at a position midway (close to the center) in the vertical direction in FIG. 4, and is biased rightward in FIG.

[0026] Next, the structure of the rocker arm 30 will be described.

[0027] 5, rocker arm 30 includes a case 31, a roller 32, and a roller shaft 33. As an example, roller 32 in this embodiment has a diameter of 16 mm.

[0028] One end 31a of the case 31 is provided with a support recess 31a1 on its inside (see FIG. 7). This support recess 31a1 is a portion into which the spherical portion at the tip of a lash adjuster provided on the cylinder head fits. The other end 31b of the case 31 is a portion that abuts against the upper end of the valve.

[0029] A through hole 31e is provided in each of a pair of side walls 31c and 31d provided in the case 31. A roller shaft 33 is inserted into these through holes 31e.

[0030] The roller 32 has a hollow cylindrical shape. The roller 32 is rotatably held by a roller shaft 33 via a bearing 34 (see FIG. 7) provided inside the roller 32. In other words, the roller 32 is rotatably held relative to the case 31 by the roller shaft 33 between the pair of side walls 31c, 31d.

[0031] As shown in FIG. 6, when rocker arm 30 is viewed from above, gaps A1 and A2 are provided between roller 32 and case 31 in the vertical direction of FIG. 6. Gaps A1 and A2 are provided with a width of approximately 2 mm in the vertical direction, and are gaps of approximately the same width. Furthermore, these gaps A1 and A2 are larger than the plate thickness of first gripping portion 12 and second gripping portion 13 (see FIG. 4), which is 1 mm. Rocker arm 30 can be gripped by inserting first gripping portion 12 and second gripping portion 13, respectively, into these gaps A1 and A2. The vertical direction in FIG. 6 is also the longitudinal direction of rocker arm 30.

[0032] Next, a description will be given of how the rocker arm assembly jig 1 grips the rocker arm 30 and how the gripped state is released.

[0033] As shown in Figure 7, the rocker arm assembly jig 1 is brought close from above the rocker arm 30 (see the downward arrow in Figure 7), and as shown in Figure 8, the first gripping portion 12 and the second gripping portion 13 are inserted into positions corresponding to the gaps A1 and A2 of the rocker arm 30, respectively.

[0034] When the operating lever 3 (see FIG. 4) is not being operated (i.e., when no external force is being applied to the second gripping portion 13 via the operating lever 3), the distance B between the tip of the first gripping portion 12 and the tip of the second gripping portion 13 is smaller than the diameter of the roller 32, as shown in FIG. 7. Therefore, as shown in FIG. 8, when the first gripping portion 12 and the second gripping portion 13 are inserted into the gaps A1 and A2, respectively, the tip of the second gripping portion 13 comes into contact with the outer circumferential surface of the roller 32. As a result, as the rocker arm assembly jig 1 moves downward, the tip of the second gripping portion 13 moves in a direction that widens along the outer circumferential surface of the roller 32 (a direction away from the first gripping portion 12, see the direction of arrow C in FIG. 8). In other words, the second gripping portion 13 moves to the right in FIG. 8 against the biasing force of the spring 15 due to the pressure from the roller 32 (this is a state in which an external force is being applied to the gripping portion by the roller 32).

[0035] By further moving the rocker arm assembly jig 1 downward, as shown in FIG. 9, the first gripping portion 12 and the second gripping portion 13 are fully inserted into the gaps A1 and A2, respectively, and the rocker arm assembly jig 1 completely grips the rocker arm 30. In FIG. 9, the first gripping portion 12 and the second gripping portion 13 are each in contact with the portion of the roller 32 that has the largest diameter in the left-right direction in the figure. The first gripping portion 12 and the second gripping portion 13 are in contact with one side and the other side of the roller 32, respectively. In this embodiment, the first gripping portion 12 is in contact with the left side of the roller 32 in FIG. 9 (the left hemisphere when the roller 32 is divided into two equal parts in the vertical direction in FIG. 9), and the second gripping portion 13 is in contact with the right side (the right hemisphere in FIG. 9).

[0036] In this way, by making the distance B between the tip of the first gripping portion 12 and the tip of the second gripping portion 13 smaller than the diameter of the roller 32, the second gripping portion 13 is pushed apart and enters the gap A2. As a result, with the tip of the first gripping portion 12 and the second gripping portion 13 inserted into the gaps A1 and A2 as shown in FIG. 9 , a force is applied by the biasing force of the spring 15 in a direction that causes the second gripping portion 13 to approach the first gripping portion 12. In other words, the first gripping portion 12 and the second gripping portion 13 can exert a gripping force on the roller 32. Note that when each gripping portion is inserted into each gap, the second gripping portion 13 is inserted into the gap A2 while abutting against the roller 32, which prevents the second gripping portion 13 from sliding against the wall surface 31f of the case 31.

[0037] By the above operation, the gripping parts 7 provided on each support part 4 grip the corresponding rocker arms 30. In this state, the worker can grip the gripping lever 2 (see FIG. 4) and move the rocker arm assembly jig 1, thereby placing each rocker arm 30 in the corresponding position on the cylinder head.

[0038] Furthermore, when releasing the gripped state of the rocker arm 30, as shown in Figure 4, while gripping the grip lever 2, the operating lever 3 is pulled toward the grip lever 2. During this operation, the link member 11 to which the operating lever 3 is connected rotates in the direction of arrow D with one end 11a (see Figure 3) as a fulcrum. In other words, the operating lever 3 connected to the link member 11 also moves in the direction of rotation in the direction of arrow D.

[0039] When the operating lever 3 rotates in the direction of arrow D, one end of each second gripping portion 13, one end of which is fixed to the operating lever 3, moves in the direction of arrow D. That is, as shown in FIG. 9, the second gripping portion 13 rotates in the direction of arrow D, with the other end abutting against the wall surface 31f on the other end 31b side of the case 31 of the rocker arm 30 as a fulcrum. At this time, the plunger 17 (see FIG. 4) is compressed to the left in FIG. 4 by the operating force on the operating lever 3. As a result, as shown in FIG. 10, the second gripping portion 13 moves to a position where it abuts against the side surface of the support portion 4 and assumes an upright position relative to the rocker arm 30. Note that, because one end of all the second gripping portions 13 is connected to the operating lever 3, the above operation causes all the second gripping portions 13 to assume an upright position relative to the rocker arm 30. This allows each rocker arm assembly jig 1 to release its grip on the rocker arm 30. In other words, by operating the operating lever 3, the gripping state of all the gripping portions 7 on the rocker arms can be released at once.

[0040] In this state, by moving the rocker arm assembly jig 1 upward, the first gripping portion 12 and the second gripping portion 13 can be retracted from the gaps A1 and A2, respectively. After retraction, by releasing the operating force on the operating lever 3, the second gripping portion 13 is pushed out by the restoring force of the spring provided on the plunger 17, and rotates in the direction opposite to the direction of arrow D, with the portion abutting against the wall surface 31f in Figure 9 as the fulcrum. This causes the second gripping portion 13 to return to the inclined position shown in Figure 4.

[0041] As described above, the rocker arm assembly jig 1 of this embodiment can grip the roller 32 with the first gripping portion 12 and the second gripping portion 13 simply by inserting the tips of the first gripping portion 12 and the second gripping portion 13 into the gaps A1, A2, and no other special action (for example, opening and closing the first gripping portion 12 or the second gripping portion 13) is required. This makes it easy to grip the rocker arm 30 with the rocker arm assembly jig 1. Furthermore, the rocker arm 30 can be gripped simply by opening and closing the second gripping portion 13, which is a flat plate, which simplifies the configuration of the rocker arm assembly jig 1, reduces costs, and makes maintenance easier.

[0042] Furthermore, by making the first gripping portion 12 a flat plate, the first gripping portion 12 can be moved along the same trajectory when inserted into the gap A1 and when retracted, preventing the first gripping portion 12 from interfering with the case 31 and hindering its movement. Also, the space required for the movement of the second gripping portion 13 when inserted and retracted can be kept to a minimum, allowing the second gripping portion 13 to be inserted and retracted even in small gaps without interfering with the case 31. Furthermore, even when the combinations of gripping portions and gaps described below are different, each gripping portion can be smoothly inserted into and retracted from each gap.

[0043] When assembling the rocker arms 30 to the cylinder head, the gripping portions 7 of the rocker arm assembly jig 1 grip each rocker arm 30 as described above. Then, the rocker arm assembly jig 1 is positioned relative to the cylinder head, and as shown in FIG. 11, the recess 31a1 (see FIG. 9) of one end 31a of the case 31 of the rocker arm 30 is aligned with the spherical portion at the tip of the lash adjuster 52 attached to the cylinder head 50, and the other end 31b of the case 31 is aligned with the upper end of the valve. In this state, the rocker arm 30 is released from its grip by the rocker arm assembly jig 1 (see FIG. 10), and the rocker arm 30 is placed in the predetermined position on the cylinder head 50 by its own weight. The rocker arm assembly jig 1 is then retracted upward. In this manner, three rocker arms 30 can be assembled to the cylinder head at once.

[0044] Incidentally, Fig. 12 is a plan view showing the state in which the rocker arm 30 is disposed in the cylinder head 50. In this embodiment, as shown in Fig. 12, the distance between the installation position of the rocker arm 30 and the wall surface 51 of the cylinder head 50 is short, and the installation position of the rocker arm 30 is disposed in a position recessed within the cylinder head 50 (a position toward the back in the direction perpendicular to the plane of the paper in Fig. 12) relative to the upper end surface of the cylinder head 50 in Fig. 12. For this reason, it is difficult to secure space outside both side walls 31c, 31d of the case 31 (on the left and right sides in Fig. 12) for inserting the gripping portions or for opening the gripping portions to release the gripping state relative to the case 31, making it difficult to grip both side surfaces of the rocker arm 30 with the gripping portions to position it in Fig. 12 and to release the gripping state.

[0045] However, as described above, the rocker arm assembly jig 1 according to this embodiment can grip two locations on the outer peripheral surface of the roller 32 to lift the rocker arm 30 and assemble it to the cylinder head. In other words, the rocker arm assembly jig 1 according to this embodiment grips the curved outer peripheral surface of the roller 32, rather than the relatively flat axial end surfaces of the roller shaft 33 of the rocker arm 30 or the outer surfaces of the surrounding side walls 31c, 31d of the case. This eliminates the need for space for gripping outside the side walls 31c, 31d of the case 31. Therefore, even in a configuration in which the distance between the assembly position of the rocker arm 30 and the wall surface 51 of the cylinder head 50 is short, the rocker arm 30 can be assembled to the cylinder head 50, and then the rocker arm assembly jig 1 can be retracted from the rocker arm 30. Furthermore, particularly in this embodiment, the first gripping portion 12 and the second gripping portion 13 can grip and release the roller 32 within the gaps A1, A2.

[0046] In the above description, the first gripping portion 12 and the second gripping portion 13 are inserted into the gap A1 and the gap A2, respectively, to grip the roller 32. However, as shown in FIG. 13 , the first gripping portion 12 can also be inserted into the gap A2 and the second gripping portion 13 can also be inserted into the gap A1 to grip the roller 32. In this case, as described with reference to FIG. 8 , the second gripping portion 12 can be inserted into the gap A1 while pushing the roller 32 along its outer circumferential surface. To release the gripped state, the gripping lever 2 is rotated in the same manner as above, so that the other end of the second gripping portion 13 abuts against the wall surface 31g on the one end 31a side of the case 31, and one end of the second gripping portion 13 is rotated, as shown in FIG. 14 . This allows the second gripping portion 13 to stand upright and retreat from the gap A1. In this way, with the rocker arm assembly jig 1 of this embodiment, regardless of the combination of gripping portions and gaps, each gripping portion can be inserted into the gap from above to grip the rocker arm 30, as shown in Figures 7 to 9. Therefore, the rocker arm assembly jig 1 of this embodiment can grip the intake-side and exhaust-side rocker arms 30 from the same direction and in the same way, improving the workability of assembling the rocker arm 30 to the cylinder head.

[0047] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0048] In this embodiment, the gripping portions of first gripping portion 12 and second gripping portion 13 are flat. However, first gripping portion 12 and second gripping portion 13 may be configured by providing a curved shape at the tip of a flat plate, as long as they can be inserted into and removed from gaps A1 and A2. [Explanation of symbols]

[0049] 1 Rocker arm assembly jig (rocker arm gripping jig) 2 gripping lever 3 Operating lever 7 Gripping part 11 Link member 12 1st grip part 13 Second grip part 30 rocker arm 31 cases 32 Roller 33 Roller shaft 50 cylinder head A1, A2 gap

Claims

1. A rocker arm gripping jig for gripping a roller rocker arm, The roller rocker arm includes a first gripping portion and a second gripping portion that respectively contact two locations on one side and the other side of the outer peripheral surface of the roller, A rocker arm gripping jig, characterized in that the distance between the first gripping portion and the second gripping portion is variable and includes a flat portion.

2. The second gripping portion may further include a biasing member that biases the second gripping portion toward the first gripping portion, 2. The rocker arm gripping jig according to claim 1, wherein the distance between the tip of the first gripping portion and the tip of the second gripping portion is smaller than the diameter of the roller.

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