Piston and connecting rod assembly device and assembly method

Abstract

This invention provides an assembly apparatus and method for a piston and connecting rod. The piston holding unit (22) has a top surface holding mechanism (50) and a skirt holding mechanism (54). The top surface holding mechanism (50) holds the top surface (48) of the piston (12). The skirt holding mechanism (54) holds the skirt (52) of the piston (12). By driving a first drive source (56), the holding state of the first holding member (58) of the top surface holding mechanism (50) on the top surface (48) can be switched. By driving the first drive source (56), the holding state of the second holding member (70) of the skirt holding mechanism (54) on the skirt can be switched. Accordingly, the piston and connecting rod can be easily and stably adjusted to a predetermined position.

Description

Technical Field

[0001] This invention relates to an assembly apparatus and method for a piston and a connecting rod. Background Technology

[0002] In existing technology, pistons and connecting rods are assembled in internal combustion engines used in vehicles such as automobiles. During assembly, the piston and connecting rod are positioned at predetermined locations on an assembly device. Then, a piston pin is fitted into the pin hole of the piston and the small end hole of the connecting rod. Accordingly, the piston and connecting rod are integrally assembled via the piston pin.

[0003] The assembly apparatus disclosed in Japanese Patent Publication No. 2008-057567 is mounted on a movable tray. The assembly apparatus includes a connecting rod support, a piston support, and a guide rod. The connecting rod support supports the small end of the connecting rod. The piston support supports the piston. The guide rod is mounted to the piston support in a liftable manner. The piston support supports the piston such that the piston pin hole of the piston is coaxially aligned with the small end hole of the connecting rod.

[0004] Next, the guide rod is raised and inserted from below into the piston pin hole of the piston and the small end hole of the connecting rod. The piston and connecting rod are positioned relative to each other by the guide rod. Then, the piston pin is inserted from above into the piston pin hole and the small end hole. The guide pin is pressed downward by the piston pin. Accordingly, the piston pin engages with the piston hole and the small end hole. The small end of the connecting rod and the piston are assembled as one unit by the piston pin. Summary of the Invention

[0005] Generally, the diameter of the piston, or the thickness or width of the connecting rod, varies depending on the displacement of the internal combustion engine. Therefore, when assembling various pistons and connecting rods of different shapes using the same assembly equipment, it is necessary to position the pistons and connecting rods in the specified positions according to their types.

[0006] In addition, retaining components are required for positioning the piston and connecting rod separately. Therefore, adjusting the position of the piston and connecting rod using retaining components is a complex process.

[0007] If the piston and connecting rod positions are not adequately adjusted by the retaining components, the piston pin bore and the small end bore of the connecting rod may become misaligned. When the piston pin is fitted into the piston pin bore and the small end bore of the connecting rod, the piston pin contacts the piston pin bore and the small end bore of the connecting rod and twists. This can easily lead to poor piston pin assembly. In particular, when the piston pin is fitted into the piston pin bore and the small end bore, and the piston pin bore and the small end bore are adjusted (self-aligned) to be coaxial using the piston pin, the piston and connecting rod may misalign. Therefore, even small errors in the piston and connecting rod can result in poor assembly.

[0008] The present invention provides an assembly apparatus for a piston and connecting rod, comprising a piston retaining platform, a connecting rod retaining platform, an intermediate retaining portion, and a piston pin insertion unit. The piston retaining platform has a lower end retaining portion for the pin hole and a guide shaft. When the small end of the connecting rod is inserted into the skirt of the piston, and the axis of the pin hole of the piston facing the vertical direction is substantially aligned with the axis of the small end hole of the small end, the lower end retaining portion holds the lower end of the pin hole. The guide shaft can move vertically relative to the lower end retaining portion and align it by passing through the pin hole and the small end hole. The connecting rod retaining platform is used to hold the large end of the connecting rod. The intermediate retaining portion... The middle portion between the small end and the large end of the connecting rod is held; the piston pin insertion unit inserts the piston pin from above when the small end hole and the pin hole are aligned. The piston and connecting rod assembly device is characterized by having a piston holding unit that holds the piston. This piston holding unit has a top surface holding mechanism, a skirt holding mechanism, and a movable mechanism. The top surface holding mechanism holds and fixes the top surface of the piston; the skirt holding mechanism holds and fixes the skirt of the piston; and the movable mechanism moves the top surface holding mechanism and the skirt holding mechanism to a fixed position that fixes the piston or to an open position that releases the piston from fixation.

[0009] According to the present invention, a piston holding unit holds a piston placed on a piston holding platform. The piston holding unit has a top surface holding mechanism and a skirt holding mechanism. The top surface holding mechanism holds and fixes the top surface of the piston. The skirt holding mechanism holds and fixes the skirt of the piston. By making the movable mechanism movable, the top surface holding mechanism and the skirt holding mechanism can be moved to switch to a fixed position where the piston is fixed. By making the movable mechanism movable, the top surface holding mechanism and the skirt holding mechanism can be moved to switch to an open position where the piston is released from fixation.

[0010] To maintain the piston's fixed position via the top surface retaining mechanism and the skirt retaining mechanism, a guide shaft is inserted into the piston's pin hole and the small end of the connecting rod, with the guide shaft passing through them. This ensures that the axis of the pin hole is approximately aligned with the axis of the small end hole at the small end of the piston. A piston pin is inserted into the pin hole and the small end hole. With the insertion of the piston pin, the small end of the connecting rod, mounted on the connecting rod retaining platform, moves in a manner that follows the pin hole. The pin hole and the small end hole are adjusted to be coaxial.

[0011] As a result, for pistons and connecting rods of different shapes, the specified position can be easily and stably adjusted with the small end bore of the connecting rod and the pin bore of the piston as coaxial. Accordingly, the piston pin can be reliably inserted into the pin bore and the small end bore, and the piston and connecting rod can be assembled by the piston pin.

[0012] The above-mentioned objects, features, and advantages should be readily understood from the following description of the embodiments with reference to the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a perspective view of the piston and connecting rod assembly device according to an embodiment of the present invention.

[0014] Figure 2 yes Figure 1 The overall top view of the assembly device shown.

[0015] Figure 3 It means Figure 2 An enlarged top view of a piston holding unit and a connecting rod holding unit in the assembly device.

[0016] Figure 4 It means in Figure 3 A partial sectional side view of the assembly device shown, showing the state of the piston and connecting rod before assembly.

[0017] Figure 5 It means Figure 1 An enlarged perspective view of the piston holding unit in the assembly device.

[0018] Figure 6 yes Figure 3 An enlarged top view of the area near the skirt holding mechanism in the assembly device.

[0019] Figure 7 It constitutes Figure 6 Enlarged front view of the second retaining component of the skirt retaining mechanism.

[0020] Figure 8 It means in Figure 4 A partially enlarged cross-sectional view of the piston skirt being held in place by a skirt holding mechanism in the assembly device.

[0021] Figure 9 It means Figure 4 An enlarged cross-sectional view of the area near the piston in the assembly device.

[0022] Figure 10 yes Figure 3 XX sectional view.

[0023] Figure 11 It means in Figure 4 A partial cross-sectional side view of the assembly device in which the piston holding unit descends after advancing to house the piston inside.

[0024] Figure 12 It means in Figure 11 A partial cross-sectional side view of the assembly device, showing the state of the skirt of the piston held in place by the skirt holding mechanism.

[0025] Figure 13 It means in Figure 12 A partial sectional side view of the assembly device in which the top surface of the piston is held in place by a top surface holding mechanism.

[0026] Figure 14 It means Figure 13 A partial sectional side view of the assembly device, showing the piston pin insertion unit descending and the piston pin abutting against the upper end of the guide shaft.

[0027] Figure 15 It means Figure 14 A partial sectional side view of the assembly device showing the piston pin being pressed downwards and beginning to insert into the upper pin hole.

[0028] Figure 16 It means Figure 15 A partial sectional side view of the assembly device in which the piston pin is pressed downward and inserted into the small end hole of the connecting rod.

[0029] Figure 17 It means Figure 16 A partial sectional side view of the assembly device, showing the state in which the piston pin is pressed downward and inserted into the pin hole below, thus completing the assembly.

[0030] Figure 18 It means Figure 17 A partial sectional side view of the assembly device in which the piston pin insertion unit rises and the top surface holding mechanism is released from its holding state on the top surface.

[0031] Figure 19 It means Figure 18 A partial sectional side view of the assembly device in which the piston holding unit moves forward, thereby releasing the skirt from its holding state.

[0032] Figure 20 It means Figure 19 A partial cross-sectional side view of the assembly device in the state where the piston holding unit moves to the rear after rising. Detailed Implementation

[0033] like Figure 1 and Figure 2 As shown, the piston and connecting rod assembly device 10 (hereinafter referred to as assembly device 10) is disposed on the assembly line 16 for assembling the piston 12 and connecting rod 14. On the assembly line 16, the assembly device 10 is disposed on a tray 20 that can move along the conveyor belt 18. The assembly device 10 positions and fixes the piston 12 and connecting rod 14 on the tray 20.

[0034] The assembly device 10 includes a piston holding unit 22, a piston holding platform 24, a connecting rod holding unit 26, and a piston pin insertion unit 34. The piston holding unit 22 holds the piston 12. The piston holding platform 24 is disposed on a tray 20. The connecting rod holding unit 26 is disposed separately from the piston holding platform 24. The connecting rod holding unit 26 is fixed to the tray 20. The piston pin insertion unit 34 inserts the piston pin 32 into the pin holes 28a and 28b of the piston 12 and the small end hole 30 of the connecting rod 14 (see reference). Figure 17 When assembling the piston 12 and connecting rod 14, the piston 12 is placed on the piston retainer 24 with the pin hole 28b facing downwards.

[0035] The assembly device 10 has two sets each of piston holding unit 22, piston holding platform 24, connecting rod holding unit 26, and piston pin insertion unit 34. The assembly device 10 is capable of assembling two sets of pistons 12 and two sets of connecting rods 14 simultaneously. The following description will focus on one set of piston holding unit 22, piston holding platform 24, connecting rod holding unit 26, and piston pin insertion unit 34 located in the width direction of the assembly device 10.

[0036] In the following explanation, for convenience, will be... Figure 1 The direction of movement of tray 20 (arrow A1) is called one side of the width direction. The direction opposite to the direction of movement of tray 20 (arrow A2) is called the other side of the width direction. The direction orthogonal to the aforementioned width direction is called the front-back direction (arrows B1 and B2). In the front-back direction, the direction toward tray 20 is called the front (arrow B1). The direction opposite to tray 20 is called the rear (arrow B2).

[0037] like Figures 1-5 As shown, the piston holding unit 22 is mounted on the support column 36. The support column 36 is erected vertically (in the direction of arrows C1 and C2) on a stand (not shown). The piston holding unit 22 is able to move up and down along the support column 36 by a drive device (not shown). The piston holding unit 22 is also able to move forward or backward in the front-back direction by a drive device (not shown). The piston holding unit 22 is fixed to the support base 40. The support base 40 is movable along the guide portion 38 of the support column 36.

[0038] The support base 40 extends in the vertical direction (direction of arrows C1 and C2). The support base 40 has a vertical base portion 42 and a horizontal base portion 44. The guide portion 38 is inserted into the vertical base portion 42 via a groove. The horizontal base portion 44 extends forward (direction of arrow B1) substantially horizontally from the upper end of the vertical base portion 42.

[0039] The piston retaining unit 22 includes a frame 46, a top surface retaining mechanism 50, and a skirt retaining mechanism 54. The frame 46 is hollow and fixed to the upper surface of the horizontal base portion 44. The top surface retaining mechanism 50 is disposed at the rear end of the frame 46. The top surface retaining mechanism 50 retains the top surface 48 of the piston 12. The skirt retaining mechanism 54 is disposed at the front end of the frame 46. The skirt retaining mechanism 54 retains the skirt 52 of the piston 12.

[0040] from Figure 2 Viewed from the vertical direction, the cross-sectional shape of frame 46 is approximately rectangular. Frame 46 is open in the vertical direction (arrows C1 and C2). The lower surface of the rear end of frame 46 is fixed to the upper surface of the horizontal base portion 44. Frame 46 extends in a generally horizontal direction, similar to the horizontal base portion 44. Frame 46 protrudes forward from the support base 40 by a predetermined length (arrow B1) and is then fixed.

[0041] The crown surface retaining mechanism 50 is housed rearward within the frame 46 (in the direction of arrow B2). The crown surface retaining mechanism 50 has a first drive source (movable mechanism) 56 and a first retaining member 58. The first drive source 56 is fixed to the inner side of the rear end wall of the frame 46. The first retaining member 58 is positioned forward of the first drive source 56 (in the direction of arrow B1). The first retaining member 58 retains the crown surface 48 of the piston 12.

[0042] The first drive source 56 is arranged along the front-rear direction of the top surface retaining mechanism 50. The first drive source 56 has a cylinder body 60, a cylinder piston (not shown), and a first rod 62. A portion of the first rod 62 protrudes outward from the front end of the cylinder body 60. Pressurized fluid is supplied to the interior of the cylinder body 60 of the first drive source 56. As pressurized fluid is supplied to the cylinder body 60, the cylinder piston and the first rod 62 move forward and backward axially (front-rear direction, in the direction of arrows B1 and B2). The rear end of the cylinder body 60 is fixed to the rear end wall of the frame 46.

[0043] A plate-shaped connecting plate 64 is installed at the front end of the first rod 62. The connecting plate 64 is orthogonal to the axis of the first rod 62. A first retaining member 58 is installed on the front surface of the connecting plate 64.

[0044] Viewed from the front-rear direction, the piston retaining unit 22 has a first retaining member 58 that is longer in the width direction (arrows A1 and A2). Near the two ends of the front end face of the first retaining member 58 in the width direction, there is a pair of retaining pins 66. The retaining pins 66 have a predetermined length along the axial direction (arrow B1). The cross-sectional shape of the retaining pins 66 is circular. The retaining pins 66 protrude forward from the front end face of the first retaining member 58 (arrow B1). The retaining pins 66 can abut against and retain the flat portion of the top surface 48 of the piston 12. In other words, the position of the pair of retaining pins 66 corresponds to the shape of the top surface 48 of the piston 12 held by the piston retaining unit 22.

[0045] When the first drive source 56 drives the first rod 62 to move forward (in the direction of arrow B1), the first retaining member 58 advances forward inside the frame 46 via the connecting plate 64 connected to the first rod 62. A pair of retaining pins 66 abut against the top surface 48 of the piston 12. The pair of retaining pins 66 hold the top surface 48 in a retained state (fixed position).

[0046] When the first drive source 56 actuates and the first lever 62 moves rearward (in the direction of arrow B2), the first retaining member 58 retracts rearward inside the frame 46. A pair of retaining pins 66 disengage from the top surface 48 of the piston 12. The top surface is in an open position (no contact between the pair of retaining pins 66 and the top surface 48).

[0047] The top surface retaining mechanism 50 switches between retaining and not retaining the top surface 48 by a pair of retaining pins 66.

[0048] like Figures 1 to 8 As shown, the skirt retaining mechanism 54 is disposed at the front end of the frame 46. The skirt retaining mechanism 54 has a pair of second drive sources 68, a second retaining member 70, and a pair of movable bodies 72. The second drive sources 68 are fixed to the outer side of the front end wall of the frame 46 (in the direction of arrow B1). The second retaining member 70 is disposed on the inner side of the front end wall of the frame 46 (in the direction of arrow B2). The second retaining member 70 retains the skirt 52 of the piston 12. The pair of movable bodies 72 are movably housed inside the second retaining member 70.

[0049] A pair of second drive sources 68 are arranged at a predetermined distance in the width direction (arrows A1, A2). Each second drive source 68 has a cylinder body 74, a cylinder piston (not shown), and a second rod 76. A portion of the second rod 76 protrudes outward from the rear end of the cylinder body 74. A portion of the second rod 76 is inserted into a hole (not shown) in the front end wall of the frame 46. Pressurized fluid is supplied to the interior of the cylinder body 74 of the second drive source 68. As pressurized fluid is supplied to the cylinder body 74, the cylinder piston and the second rod 76 move forward and backward axially (in the front-back direction, arrows B1, B2). The rear end of the cylinder body 74 is fixed to the front end wall of the frame 46.

[0050] like Figures 6-8 As shown, the second retaining member 70 is a block with the same cross-sectional shape along the axial direction (arrows B1 and B2). The second retaining member 70 has a pair of first reference portions 78, a recess 80, a pair of second reference portions 82, and a flat portion 84. Viewed from the front-rear direction, the first reference portions 78 are disposed on both sides in the width direction. The recess 80 is disposed between one first reference portion 78 and the other first reference portion 78. The second reference portion 82 is disposed radially inside the first reference portion 78. The flat portion 84 is disposed in the direction opposite to the opening direction of the recess 80 (arrow C2 direction).

[0051] The front end of the second retaining member 70 is fixed to the front end face of the frame 46. The front end of the second retaining member 70 is fixed approximately at the center of the width direction of the front end face of the frame 46. The recess 80 of the second retaining member 70 opens downward (in the direction of arrow C1). The flat portion 84 of the second retaining member 70 is located approximately on the same plane as the upper end of the front end face of the frame 46. The flat portion 84 protrudes rearward (in the direction of arrow B2) from the front end face of the frame 46 by a predetermined length.

[0052] The first reference portion 78 is arranged in pairs on both sides of the second retaining member 70 in the width direction. The cross-sectional shape of the first reference portion 78 is an arc shape that bulges outward in the radial direction. The first reference portion 78 is bent with a first radius R1. The first reference portion 78 extends from the recess 80 to the flat portion 84. The inner peripheral surface of the skirt 52 of the piston 12 abuts against the outer peripheral surface of the first reference portion 78 and is retained thereby.

[0053] The recess 80 extends outward in the width direction from approximately the center of the second retaining member 70 for a predetermined width. The recess 80 extends in a straight line along the front-rear direction of the second retaining member 70. When the piston 12 and the connecting rod 14 are assembled, a portion of the connecting rod 14 can be inserted into the recess 80.

[0054] The second reference portion 82 is disposed at a position radially inward of the first reference portion 78. The cross-sectional shape of the second reference portion 82 is an arc shape bulging outward in the radial direction. The second reference portion 82 is bent with a second radius R2. The second reference portion 82 extends from the concave portion 80 to the flat portion 84. The second reference portion 82 protrudes a predetermined height rearward (in the direction of arrow B2) from the front end surface of the first reference portion 78. At the rear end of the second holding member 70, the first reference portion 78 and the second reference portion 82 are stepped in the front-rear direction.

[0055] On the outer peripheral surface of the second reference portion 82, the skirt portion 52 of another piston 12 having a different shape and a diameter smaller than that of the piston 12 held by the first reference portion 78 can be abutted and held. In the second holding member 70, the first reference portion 78 and the second reference portion 82 are respectively arranged in pairs with the concave portion 80 as the center and separated in the width direction (in the directions of arrows A1 and A2).

[0056] The second holding member 70 has a pair of through holes 86. The pair of through holes 86 are opened at positions straddling the first reference portion 78 and the second reference portion 82. The cross-sectional shape of the through hole 86 is an arc shape. The through hole 86 is bent in a manner that bulges outward in the radial direction corresponding to the first reference portion 78 and the second reference portion 82. The circumferential length of the through hole 86 is shorter than the circumferential lengths of the first reference portion 78 and the second reference portion 82. The through hole 86 is cut on the outer peripheral surface of the second reference portion 82.

[0057] The through hole 86 has a predetermined width toward the radial inside. The through hole 86 penetrates in the front-rear direction of the second holding member 70 with the same cross-sectional shape. A movable body 72 is accommodated inside the through hole 86. The through hole 86 and the movable body 72 have the same shape. The through hole 86 faces a pair of second drive sources 68 across the front end wall of the frame 46.

[0058] The cross-sectional shape of the movable body 72 is an arc shape. The cross-sectional shape of the movable body 72 is the same corresponding to the cross-sectional shape of the through hole 86. The movable body 72 is a block. The movable body 72 has the same cross-sectional shape along the axial direction (in the directions of arrows B1 and B2). The movable body 72 is accommodated inside the through hole 86 in a manner that it can move along the axial direction. The axial length of the movable body 72 is shorter than the axial length of the through hole 86, that is, the axial length of the second holding member 70.

[0059] The movable body 72 faces a pair of second drive sources 68 across the front end wall of the frame 46.

[0060] The outer peripheral surface of the movable body 72 has a third radius R3. As Figure 7 shown, the radius (third radius R3) of the outer peripheral surface of the movable body 72 is larger than the second radius R2 of the second reference portion 82 (R2 < R3). The radius (third radius R3) of the outer peripheral surface of the movable body 72 is smaller than the first radius R1 of the first reference portion 78 (R3 < R1).

[0061] The first reference portion 78 can hold the inner peripheral surface of the skirt portion 52 having a first inner diameter. The second reference portion 82 can hold the inner peripheral surface of the skirt portion 52 having a second inner diameter that is smaller than the first inner diameter. The outer peripheral surface of the movable body 72 can hold the inner peripheral surface of the skirt portion 52 having a third inner diameter that is smaller than the first inner diameter and larger than the second inner diameter.

[0062] In the second retaining member 70, by using the first reference part 78, the second reference part 82 and the movable body 72, three pistons 12 with different inner circumference diameters of the skirt 52 can be selectively positioned and retained.

[0063] The rear end of the second rod 76 of the second drive source 68 is connected to the front end of the movable body 72 inside the through hole 86. By driving the second drive source 68, the movable body 72 can move along the through hole 86 via the second rod 76. By moving the movable body 72 rearward (in the direction of arrow B2), the movable body 72 protrudes outward from the rear end of the second retaining member 70 through the through hole 86.

[0064] The movable body 72 moves forward (in the direction of arrow B1) and is completely housed inside the through hole 86. The movable body 72 does not protrude to the outside of the second retaining member 70.

[0065] The second retaining member 70 has a receiving hole (engaging mechanism) 88. The receiving hole 88 is located on the side wider than the opening of the recess 80. The receiving hole 88 opens downwards (in the direction of arrow C1). The receiving hole 88 is recessed upwards (in the direction of arrow C2) from the lower surface of the second retaining member 70 to a predetermined depth. The cross-sectional shape of the receiving hole 88 is rectangular, capable of accommodating the engaging portion 158 of the connecting rod retaining unit 26 described later. Figure 11 As shown, when the piston retaining unit 22 is moved toward the connecting rod retaining unit 26, the engaging portion 158 of the connecting rod retaining unit 26 is received in the receiving hole 88 (see reference). Figure 7 ).

[0066] like Figures 1-4 and Figure 9 As shown, the piston holding platform 24 is disposed on the upper surface near the rear end of the tray 20. The piston holding platform 24 has a first base 90, a guide shaft 92, and a locking mechanism 93. The first base 90 holds the piston 12. The guide shaft 92 is mounted on the first base 90 in a liftable manner. The locking mechanism 93 is mounted on the first base 90. The locking mechanism 93 restricts the upward movement of the guide shaft 92 after it has descended.

[0067] The first base 90 protrudes upward from the tray 20 (in the direction of arrow C2). A piston bearing member (pin hole lower end retaining part) 94 is connected to the upper end of the first base 90. The piston bearing member 94 is cylindrical. The first base 90 and the piston bearing member 94 are connected coaxially. The guide shaft 92 is housed inside the first base 90 and the piston bearing member 94 in a manner that allows it to move in the vertical direction (in the directions of arrows C1 and C2). When assembling the piston 12 and the connecting rod 14, the lower end of the pin hole 28b of the piston 12 abuts against the upper end of the piston bearing member 94. Accordingly, the piston 12 is positioned and held in the vertical direction (in the directions of arrows C1 and C2) by the piston bearing member 94.

[0068] like Figure 4 and Figure 9 As shown, the locking mechanism 93 is mounted on the first base 90 orthogonally to the axial direction (directions of arrows C1 and C2) of the guide shaft 92. The locking mechanism 93 has a cylindrical body 96, a plunger 98, and a spring 100. The cylindrical body 96 is pressed into the first base 90. The plunger 98 is spherical. The plunger 98 is movably housed inside the cylindrical body 96. The spring 100 applies force to the plunger 98 along the cylindrical body 96. The top end of the cylindrical body 96 faces the outer circumferential surface of the movable rod 104 constituting the guide shaft 92. The top end of the cylindrical body 96 is open. Inside the cylindrical body 96, the plunger 98 is forcefully pressed against the movable rod 104 by the spring 100. The plunger 98 protrudes outward from the top end of the cylindrical body 96.

[0069] A plunger 98 protrudes from the top of the cylindrical body 96. The plunger 98 engages with an engagement hole 102 in the movable rod 104. The plunger 98 also engages with an engagement hole 102 formed on the outer peripheral surface of the movable rod 104, as described later. Accordingly, when the movable rod 104 descends below the piston 12, the upward movement of the movable rod 104 is restricted by the plunger 98. The plunger 98 functions as a locking mechanism capable of restricting the upward movement of the movable rod 104 (see reference). Figure 17 ).

[0070] The guide shaft 92 includes: a movable rod 104, which is vertically and retractably disposed on the first base 90; and pressing members 106, which are spaced apart from each other along the circumference of the movable rod 104. The lower end of the movable rod 104 is housed inside the first base 90. The pressing members 106 are exposed to the outside through a window (not shown) that opens on the outer peripheral surface of the movable rod 104.

[0071] like Figures 1-4 , Figure 8 and Figure 9As shown, the movable rod 104 is a hollow cylindrical shape. The movable rod 104 is raised within the first base 90 by the elastic force of a spring (not shown). A cover 108 is mounted on the upper end of the movable rod 104. The cover 108 blocks the upper end of the movable rod 104. When the piston 12 and connecting rod 14 are assembled via the piston pin 32, as... Figure 14 As shown, the lower end of the piston pin 32, which is held in the piston pin insertion unit 34, abuts against the cover portion 108. Accordingly, the piston pin 32 and the guide shaft 92 are positioned and held substantially coaxially.

[0072] The pressing member 106 is forced radially outward by a spring (not shown). When the pressing member 106 is pressed radially inward, it is housed inside the movable rod 104 and does not protrude from the outer peripheral surface of the movable rod 104 via the window.

[0073] like Figures 1-4 and Figure 8 As shown, the link holding unit 26 is disposed on the upper surface of the tray 20. The link holding unit 26 has a large end holding platform (link holding platform) 112, an intermediate holding portion 116, and a small end bearing member (small end bearing member) 118. The large end holding platform 112 holds the large end 14b of the link 14. The intermediate holding portion 116 holds the rod portion (intermediate portion) 114 located between the large end 14b and the small end 14a of the link 14. The small end bearing member 118 is movable along the front-back direction (arrows B1 and B2) of the assembly device 10. The small end bearing member 118 holds the small end 14a.

[0074] The large end retaining platform 112 is positioned near the front end of the tray 20, moving forward (in the direction of arrow B1) from the guide shaft 92. In the longitudinal direction of the tray 20, the large end retaining platform 112 is arranged approximately in a straight line with the guide shaft 92 (see reference). Figure 2 and Figure 3 The large end retaining platform 112 has a second base 120 and a retaining plate 122. The second base 120 is fixed to the upper surface of the tray 20. The second base 120 is erected vertically upward from the tray 20 (in the direction of arrow C2). The retaining plate 122 is mounted on the upper end of the second base 120. The retaining plate 122 is movable in the up and down direction (in the directions of arrows C1 and C2).

[0075] The upper part of the retaining plate 122 has a generally horizontally extending flat retaining surface. The retaining surface is a generally horizontally extending flat surface. The lower surface of the large end 14b of the connecting rod 14 is mounted and held on the retaining surface. The retaining plate 122 can be adjusted in the vertical direction (direction of arrows C1, C2) by a drive mechanism not shown. The height of the retaining plate 122 can be adjusted according to the shape of the connecting rod 14. The large end 14b of the connecting rod 14 is mounted on the large end retaining table 112 containing the retaining plate 122. The large end 14b of the connecting rod 14 is held on the large end retaining table 112 in a manner that allows it to move horizontally.

[0076] like Figures 1-4 , Figure 8 and Figure 10 As shown, the intermediate retaining portion 116 is disposed between the guide shaft 92 and the large end retaining platform 112 in the front-rear direction (arrows B1 and B2) of the assembly device 10. The intermediate retaining portion 116 is aligned in a straight line with the guide shaft 92 and the large end retaining platform 112 in the front-rear direction. The intermediate retaining portion 116 has a base 124, a slider 126, and a retaining arm 128. The base 124 is fixed to the rear end of the retaining plate 122. The slider 126 is movable relative to the base 124 in the front-rear direction (arrows B1 and B2). The retaining arm 128 is fixed to the upper surface of the slider 126. The retaining arm 128 retains the rod portion 114 of the connecting rod 14.

[0077] like Figure 4 As shown, the base 124 has a vertical portion 130 and a parallel portion 132. Viewed from the width direction of the link holding unit 26, the vertical portion 130 is disposed at the front end of the link holding unit 26. The vertical portion 130 extends in the vertical direction (arrows C1 and C2). The parallel portion 132 extends rearward from the lower end of the vertical portion 130 (arrow B2) in a manner orthogonal to the vertical portion 130. The cross-sectional shape of the base 124 is the shape of the capital letter L.

[0078] The upper end of the vertical portion 130 is fixed to the rear end of the retaining plate 122. The parallel portion 132 is disposed below the retaining plate 122 (in the direction of arrow C1). The parallel portion 132 is disposed parallel to the retaining plate 122 and the tray 20. The parallel portion 132 protrudes rearward from the vertical portion 130 (in the direction of arrow B2).

[0079] The vertical part 130 has a threaded hole 134. For example... Figure 10 As shown, the threaded hole 134 is positioned from the center of the vertical portion 130 in the width direction to the other side in the width direction (in the direction of arrow A2). The threaded hole 134 extends along the front-back direction of the base 124. A support bolt 136 is screwed into the threaded hole 134.

[0080] The support bolt 136 is elongated along the axial direction (front-back direction, arrows B1 and B2). The support bolt 136 passes through the bolt hole 140 of the flange portion 138 of the sliding member 126 (described later). The support bolt 136 has a threaded portion 142 at its front end. By screwing the threaded portion 142 into the threaded hole 134, the support bolt 136 is fixed to the vertical portion 130 of the base 124. The support bolt 136 protrudes approximately horizontally rearward (arrow B2 direction) from the vertical portion 130. The rear end of the support bolt 136 has a head 144 that is radially outwardly enlarged compared to the threaded portion 142.

[0081] The slider 126 is capable of moving in the front-rear direction along the guide rail 146 on the upper surface of the parallel portion 132. That is, the slider 126 is capable of moving parallel to the parallel portion 132. The front end of the slider 126 has a flange portion 138 that protrudes to the other side in the width direction of the slider 126 (in the direction of arrow A2).

[0082] The flange portion 138 has a bolt hole 140. The bolt hole 140 extends through the flange portion 138 in the front-to-back direction (arrows B1 and B2). The middle portion of the axial support bolt 136 is inserted into the bolt hole 140. A return spring 148 is clamped between the flange portion 138 and the head 144 of the support bolt 136.

[0083] The return spring 148 is a helical spring. The elastic force of the return spring 148 applies a force to the slider 126 forward (in the direction of arrow B1) via the flange portion 138. The slider 126 is always subjected to a force from the return spring 148 in a direction away from the guide shaft 92 (in the direction of arrow B1).

[0084] A retaining arm 128 is disposed on the upper surface of the slider 126. The retaining arm 128 protrudes upward from the upper surface (in the direction of arrow C2). The retaining arm 128 is located in the width direction of the slider 126. Figure 2 and Figure 3 In the middle (in the direction of arrows A1 and A2), they are arranged in pairs at a predetermined interval. The rod portion 114 of the connecting rod 14 is inserted into and held between a pair of retaining arms 128 (see reference). Figure 7 The upper ends of each retaining arm 128 are bent outward in the width direction in a manner separate from each other. This improves the insertability of the link 14 when it is inserted from above between a pair of retaining arms 128.

[0085] like Figure 2 and Figure 4 As shown, the slider 126 has a locking pin 150. The locking pin 150 is forced downward (in the direction of arrow C1) by the spring force of a spring (not shown). The slider 126 is then guided by a return spring 148 (see reference). Figure 10The slider 126 moves forward (in the direction of arrow B1) due to the elastic force. When the slider 126 moves forward and returns to its initial position, the locking pin 150 is inserted into the pin hole 152 of the guide rail 146. Accordingly, the movement of the slider 126 in the forward and backward directions (in the directions of arrows B1 and B2) is restricted by the locking pin 150.

[0086] like Figures 2-4 As shown, the small end bearing member 118 is connected to the rear end of the slider 126 of the intermediate retaining part 116. The small end bearing member 118 has a main body 154, a bearing plate 156, and a locking part 158, wherein the main body 154 is fixed to the upper surface of the slider 126; the bearing plate 156 is fixed to the upper surface of the main body 154; and the locking part 158 ​​is mounted on the side of the main body 154 in the width direction.

[0087] The main body 154 has a rectangular cross-sectional shape. The main body 154 is a block. The main body 154 is mounted on the slider 126 in a way that protrudes upward (in the direction of arrow C2). The main body 154 is aligned in a straight line with the guide shaft 92 in the front-rear direction of the small end bearing member 118.

[0088] The support plate 156 is made of sheet metal. The support plate 156 is fixed to the rear end (in the direction of arrow B2) of the upper surface of the main body 154. The support plate 156 protrudes rearward from the main body 154 by a predetermined length. The support plate 156 extends horizontally (in the direction of arrows B1 and B2). The support plate 156 is parallel to the retaining plate 122 of the large end retaining platform 112. The support plate 156 has a cutout (not shown) facing forward. When the support plate 156 moves toward the guide shaft 92, the cutout prevents the support plate 156 from contacting the guide shaft 92.

[0089] The engaging portion 158 is mounted on the width-direction side of the main body 154. The engaging portion 158 protrudes from the width-direction side of the main body 154 in the width direction (arrow A1 direction). When assembling the piston 12 and connecting rod 14, the engaging portion 158 is received in the receiving hole 88 (see reference 158) by lowering the piston holding unit 22 toward the connecting rod holding unit 26. Figure 7 and Figure 11 ).

[0090] like Figure 1 and Figure 4As shown, the piston pin insertion unit 34 is positioned above the tray 20, that is, above the piston holding unit 22 and the connecting rod holding unit 26 (in the direction of arrow C2). The piston pin insertion unit 34 has a pin holding portion 164. The pin holding portion 164 is capable of holding the piston pin 32 from the inside. The piston pin insertion unit 34, including the pin holding portion 164, can be moved up and down in a vertical direction by a moving device (not shown). By moving the piston pin insertion unit 34 up and down in a vertical direction, the pin holding portion 164 approaches or moves away from the pin holes 28a and 28b of the piston 12 and the small end hole 30 of the connecting rod 14.

[0091] Next, refer to Figure 4 , Figures 11-20 The operation of the assembly device 10 for the piston 12 and connecting rod 14 will be explained. For example... Figure 4 As shown, the initial state is when the piston holding unit 22 moves backward (in the direction of arrow C2) from the position above the tray 20.

[0092] First, such as Figure 4 As shown, the loading process is carried out: the piston 12 and the connecting rod 14 are loaded on the piston holding platform 24 and the large end holding platform 112 mounted on the tray 20.

[0093] In this process, the piston 12 is configured as follows. Pin holes 28a and 28b open in the vertical direction (arrows C1 and C2). It is configured with the top surface 48 facing rearward (arrow B2) and the skirt 52 facing forward (arrow B1). The small end 14a of the connecting rod 14 is inserted between the pin holes 28a and 28b of the piston 12. In the piston retainer 24, the lower end of the pin hole 28b abuts against the upper end of the piston bearing member 94. The pin holes 28a and 28b and the small end hole 30 are approximately straight in the vertical direction (arrows C1 and C2). The piston 12 is axially positioned and held in the piston retainer 24.

[0094] The large end 14b of the connecting rod 14 is placed on the large end retaining platform 112 of the connecting rod retaining unit 26. The large end 14b is placed horizontally on the large end retaining platform 112. The small end 14a of the connecting rod 14 is held between the pin hole 28a and the pin hole 28b of the piston 12. At this time, the large end 14b of the connecting rod 14 is not simply placed on the retaining plate 122 fixed to the large end retaining platform 112. Therefore, the connecting rod 14 can move on the connecting rod retaining unit 26 in the horizontal longitudinal direction and the width direction.

[0095] On the piston retainer 24, the movable rod 104 of the guide shaft 92 is raised by the elastic force of a spring (not shown). The movable rod 104 is inserted into and passes through pin holes 28a, 28b and small end hole 30 in the vertical direction (arrow C2 direction). The pressing member 106 of the movable rod 104 is forced radially outward inside the pin holes 28a, 28b and small end hole 30. Accordingly, the pin holes 28a, 28b and small end hole 30 are adjusted to be approximately coaxial by the pressing member 106. The piston 12 and connecting rod 14 are in a pre-assembled state (see reference). Figure 9 )

[0096] Specifically, by inserting the guide shaft 92 into the small end hole 30, the small end portion 14a having the small end hole 30 moves horizontally along the large end holding platform 112 in a manner that follows the guide shaft 92. As the link 14 moves horizontally, the axis of the small end hole 30 and the axis of the guide shaft 92 are aligned to be approximately aligned.

[0097] like Figure 10 As shown, in the linkage holding unit 26, the slider 126 moves forward (in the direction of arrow B1) by the elastic force of the return spring 148. The small end bearing member 118 moves away from the guide shaft 92. Therefore, when the guide shaft 92 rises, contact between the guide shaft 92 and the small end bearing member 118 can be avoided.

[0098] A spring ring 166 is installed below the pin hole 28b of piston 12 (see reference). Figure 9 The spring ring 166 is generally C-shaped and has an elastic force that applies a radially outward force. The spring ring 166 is pre-installed in the annular groove before the piston 12 and connecting rod 14 are assembled.

[0099] After pre-assembling piston 12 and connecting rod 14, as Figure 1 and Figure 2 As shown, tray 20 moves along conveyor belt 18. Tray 20 moves to a position below (in the direction of arrow C1) the piston pin insertion unit 34. Accordingly, as... Figure 4 As shown, the guide shaft 92 (pin holes 28a, 28b and small end hole 30) and the pin holding part 164 of the piston pin insertion unit 34 (see reference) Figure 1 They face each other in the vertical direction (arrows C1 and C2). The guide shaft 92 and the pin retainer 164 are located at a predetermined distance apart in the vertical direction. At the lower end of the pin retainer 164, a piston pin 32 is pre-held in a downward (arrow C1) and coaxial manner.

[0100] Next, as Figure 11As shown, the piston holding unit 22 is moved horizontally forward (in the direction of arrow B1) from the clearance position. The piston holding unit 22 is positioned opposite the tray 20 above it (opposite position). Figure 11 (Refer to the shape of the double-dotted line). Then, the piston holding unit 22 is lowered onto the tray 20. The piston 12 and the small end 14a of the connecting rod 14 are housed inside the frame 46 (piston holding unit moving process).

[0101] Accordingly, the first retaining member 58 of the top surface retaining mechanism 50 of the piston retaining unit 22 faces the top surface 48 of the piston 12. The first retaining member 58 and the top surface 48 of the piston 12 are arranged at a predetermined distance apart in the front-rear direction. The first retaining member 58 is located behind the top surface 48 (in the direction of arrow B2). The second retaining member 70 of the skirt retaining mechanism 54 faces the skirt 52 of the piston 12. The second retaining member 70 and the skirt 52 are arranged at a predetermined distance apart in the front-rear direction. The second retaining member 70 is located in front of the skirt 52 (in the direction of arrow B1) (retention preparation step).

[0102] In other words, the top surface retaining mechanism 50 and the skirt retaining mechanism 54 are respectively arranged at a predetermined distance from the piston 12 in the front-back direction (arrows B1 and B2).

[0103] As the piston retaining unit 22 descends, the engaging portion 158 of the small end bearing member 118 is inserted into the receiving hole 88 of the second retaining member 70. As the piston retaining unit 22 descends, the rod portion 114 of the connecting rod 14 and the small end bearing member 118 are received inside the recess 80 (see reference). Figure 7 That is, when the piston holding unit 22 is lowered, it is possible to prevent the recess 80 from contacting the rod portion 114 and the small end bearing member 118.

[0104] Next, as Figure 12 As shown, the holding process of the piston 12 (piston holding process) is part of the holding process of the skirt 52 (skirt holding process).

[0105] In this process, the piston holding unit 22 is moved horizontally rearward (in the direction of arrow B2). The rear end of the second holding member 70 is inserted into the skirt 52. Furthermore, the outer peripheral surface of the first reference portion 78 of the first radius R1 or the second reference portion 82 of the second radius R2 abuts against the inner peripheral surface of the skirt 52. Accordingly, the inner peripheral surface of the skirt 52 is held by the second holding member 70. The radial movement of the skirt 52 is restricted by the second holding member 70 (see reference). Figure 8 ).

[0106] Through the first radius R1 (refer to) Figure 7The first reference portion 78 can hold the skirt portion 52 (piston 12) having an inner circumferential surface with the same radius as the first reference portion 78. The second reference portion 82 with a second radius R2 smaller than the first radius R1 can hold the skirt portion 52 of the piston 12 with a diameter smaller than that of the piston 12 held by the first reference portion 78.

[0107] Next, the case of a piston 12 whose diameter is different from that of the two types of pistons 12 held by the movable body 72 and the first reference part 78 and the second reference part 82 will be described.

[0108] First, before performing the skirt holding process described above, the second drive source 68 of the skirt holding mechanism 54 is driven. As the second drive source 68 is driven, the second lever 76 moves rearward (in the direction of arrow B2), and a pair of movable bodies 72 are pressed rearward by the second lever 76. The movable bodies 72 move along the through hole 86, causing the rear end of the movable body 72 to protrude rearward (in the direction of arrow B2) beyond the second reference portion 82. The movable bodies 72 protrude rearward (in the direction of arrow B2) from the rear end face of the second holding member 70.

[0109] Then, the rear end of the second retaining member 70 is inserted into the interior of the skirt 52. Accordingly, the outer peripheral surface of the movable body 72 with a third radius R3 abuts against the inner peripheral surface of the skirt 52. Therefore, the inner peripheral surface of the skirt 52 is held by the second retaining member 70. By restricting the radial movement of the skirt 52 by the movable body 72, the skirt 52 can be held in place (engaging process).

[0110] When the inner peripheral surface of the skirt 52 is held by the second reference part 82, the movable body 72 is moved forward (in the direction of arrow B1) by driving the second drive source 68. The movable body 72 is housed inside the through hole 86. Accordingly, the movable body 72 does not protrude to the outside of the second holding member 70. Accordingly, the outer peripheral surface of the second reference part 82 can be brought into contact with the inner peripheral surface of the skirt 52 and held therein, without the movable body 72 contacting the skirt 52.

[0111] Thus, the second retaining member 70 has a pair of movable bodies 72 capable of moving axially (front-back direction) and two reference portions with different radii, namely, the first reference portion 78 and the second reference portion 82. Therefore, the skirt 52 of three pistons 12 with different diameters can be retained by a single piston retaining unit 22.

[0112] During the skirt 52 holding process performed by the skirt holding mechanism 54, the second holding member 70 moves toward the piston 12. At this time, the engaging part 158 ​​is received in the receiving hole 88 and moves toward the piston 12. As the engaging part 158 ​​moves, the small end bearing member 118 moves rearward (in the direction of arrow B2) together with the slider 126. At this time, the slider 126 moves against the spring force of the return spring 148. As the slider 126 moves, the locking pin 150 disengages from the pin hole 152 of the guide rail 146. Accordingly, the movement restriction state of the slider 126 in the front-rear direction is released. The slider 126 becomes able to move rearward (in the direction of arrow B2).

[0113] The bearing plate 156 moves toward the small end 14a as the small end bearing member 118 moves rearward (in the direction of arrow B2). The lower surface of the small end 14a abuts against the bearing plate 156 and is held in place. The small end 14a of the link 14 is held by the bearing plate 156 so that it can move in the horizontal direction (in the directions of arrows B1 and B2). The large end 14b of the link 14 is held by the retaining plate 122 so that it can move in the horizontal direction.

[0114] Next, as Figure 13 As shown, a top surface 48 holding process (top surface holding process) is performed, in which the top surface 48 of the piston 12 is held by the top surface holding mechanism 50. Pressurized fluid is supplied to the cylinder body 60 of the first drive source 56. The pressurized fluid causes a cylinder piston (not shown) and a first rod 62 to move toward the piston 12. As the first rod 62 moves, the connecting plate 64 and the first holding member 58 move toward the top surface 48. The tips of a pair of holding pins 66 abut against the top surface 48. Accordingly, the flat portion of the top surface 48 in the piston 12 is held forward (in the direction of arrow B1) by the first holding member 58.

[0115] As a result, the top surface 48 of the piston 12 is held by the top surface holding mechanism 50 that constitutes the piston holding unit 22. The skirt 52 of the piston 12 is held by the skirt holding mechanism 54. Accordingly, the piston 12 is positioned and held in a predetermined position in the front-rear direction of the assembly device 10.

[0116] Next, as Figure 14 As shown, a pin insertion process (piston pin insertion process) is performed, in which the piston pin 32 is inserted relative to the piston 12 and connecting rod 14. In this process, after the piston pin insertion unit 34 is arranged coaxially with the pin holes 28a, 28b and the small end hole 30, the piston pin insertion unit 34 is lowered. Then, the lower end of the piston pin 32 abuts against the cover portion 108 of the guide shaft 92 (abutment process).

[0117] Then, as Figure 15As shown, by further lowering the piston pin insertion unit 34, the movable rod 104 is pressed downwards (in the direction of arrow C1) via the cover portion 108 (pressing-down process). For example... Figure 15 As shown, the lower end of the piston pin 32 is inserted into a pin hole 28a. Accordingly, the axis of the piston pin 32 and the axis of the pin hole 28a are aligned. The piston pin 32 and the pin hole 28a are positioned relative to each other.

[0118] In the insertion process of the piston pin 32, such as Figure 16 As shown, the movable rod 104 is pressed down by the piston pin insertion unit 34. The piston pin 32 descends together with the movable rod 104. The lower end of the piston pin 32, which passes through a pin hole 28a, is inserted into the small end hole 30 of the connecting rod 14. Accordingly, the small end hole 30 moves in a manner that follows the lower end of the piston pin 32, and consequently, the connecting rod 14, including the small end 14a, moves horizontally in a state where it is placed on the small end bearing member 118 and the large end holding platform 112.

[0119] Accordingly, by inserting a piston pin 32 into a pin hole 28a and a small end hole 30, the relative positions of the piston 12 and the connecting rod 14 are adjusted so that the pin hole 28a and the small end hole 30 become coaxial. At this time, the lower end of the piston pin 32 is properly guided into the small end hole 30 by the chamfered portion of the axial end of the small end hole 30.

[0120] Then, in the insertion process of piston pin 32, as Figure 17 As shown, the piston pin insertion unit 34 is lowered, and the movable rod 104 is pressed down while the piston pin 32 is further inserted downwards (in the direction of arrow C1). Accordingly, the lower end of the piston pin 32 is inserted into the pin hole 28b through the small end hole 30. The lower end of the piston pin 32 abuts against the pre-installed spring ring 166 that protrudes radially inwards. The insertion of the piston pin 32 is completed by the piston pin 32 being held in place by the spring ring 166. Accordingly, the piston 12 is assembled to the small end 14a of the connecting rod 14 via the piston pin 32. The piston pin 32 is in the completed insertion position, located at the desired insertion position into the small end 14a of the piston 12 and the connecting rod 14.

[0121] like Figure 17 As shown, the movable rod 104 of the guide shaft 92 is completely disengaged from the pin hole 28b and located below the piston 12 (in the direction of arrow C1). The plunger 98 of the locking mechanism 93 is forced against the movable rod 104 by the spring force of the spring 100. The plunger 98 engages with the engagement hole 102 of the movable rod 104. The engagement hole 102 is located on the outer peripheral surface of the movable rod 104. The engagement hole 102 is recessed radially inward from the outer peripheral surface of the movable rod 104. Accordingly, the upward movement of the movable rod 104 is restricted by the plunger 98, resulting in a locked state (locking operation).

[0122] With the movable rod 104 locked, a spring ring 166 is installed in the annular groove above the pin hole 28a of the piston 12. The spring ring 166 protrudes radially inward from the inner circumferential surface of the pin hole 28a. Therefore, with the piston pin 32 inserted into the pin holes 28a and 28b, the piston pin 32 cannot move axially due to the pair of spring rings 166. The pair of spring rings 166 prevents the piston pin 32 from falling out of the pin holes 28a and 28b.

[0123] Next, as Figure 18 As shown, the removal process is carried out to take out the assembled piston 12 and connecting rod 14.

[0124] First, after the piston pin insertion unit 34 is raised, pressurized fluid is supplied to the first drive source 56 of the top surface holding mechanism 50. Accordingly, the cylinder piston (not shown) and the first rod 62 of the first drive source 56 move rearward (in the direction of arrow B2). As the first rod 62 retracts, the first holding member 58 moves away from the piston 12 via the connecting plate 64 (in the direction of arrow B2). This results in an open position, releasing the pair of holding pins 66 from holding the top surface 48 of the piston 12.

[0125] Next, as Figure 19 As shown, the piston holding unit 22 is moved horizontally forward (in the direction of arrow B1). Accordingly, the second holding member 70 disengages from the piston 12, reaching an open position where it releases its hold on the skirt 52. As the second holding member 70 moves forward, the small end bearing member 118 and the slider 126 move forward integrally (in the direction of arrow B1) via the engaging portion 158. Then, the locking pin 150 is inserted into the pin hole 152 of the guide rail 146. This results in a locked state where the movement of the slider 126 and the small end bearing member 118 in the front-back direction (in the directions of arrows B1 and B2).

[0126] like Figure 20 As shown, after the piston holding unit 22 rises along the guide portion 38 of the support column 36 (refer to the shape of the double-dotted line), it moves horizontally rearward (in the direction of arrow B2). Accordingly, the piston holding unit 22 is transferred from a state located above the tray 20 (in the direction of arrow C2) to an initial state of rearward clearance. By the rearward clearance of the piston holding unit 22, the top of the tray 20 is opened, and the assembly formed by the piston 12 and the connecting rod 14 is removed upward (in the direction of arrow C2) from the piston holding table 24 and the large end holding table 112.

[0127] When the assembly of piston 12 and connecting rod 14 is removed from piston holding platform 24, the upward movement of movable rod 104 is restricted by locking mechanism 93 (see reference). Figure 17Therefore, it is possible to prevent the movable rod 104 from popping out upwards (in the direction of arrow C2). When the small end bearing member 118 is positioned forward (in the direction of arrow B1) away from the piston 12, the movement of the small end bearing member 118 is restricted by the locking pin 150. Therefore, it is possible to prevent the small end bearing member 118 from contacting the piston 12.

[0128] As described above, the assembly apparatus 10 according to this embodiment includes a piston holding unit 22. The piston holding unit 22 holds the piston 12 placed on the piston holding platform 24. The piston holding unit 22 includes a top surface holding mechanism 50 and a skirt holding mechanism 54. The top surface holding mechanism 50 holds and fixes the top surface 48 of the piston 12. The skirt holding mechanism 54 holds and fixes the skirt 52 of the piston 12. By driving the first drive source 56, the holding state of the first holding member 58 of the top surface holding mechanism 50 on the top surface 48 can be switched. By moving the piston holding unit 22, the holding state of the second holding member 70 of the skirt holding mechanism 54 on the skirt 52 can be switched.

[0129] The piston 12 is held by the top retaining mechanism 50 and the skirt retaining mechanism 54. Then, the small end 14a of the connecting rod 14 is inserted between the pin holes 28a and 28b of the piston 12. After aligning the pin holes 28a and 28b with the small end hole 30 of the small end 14a in a substantially coaxial manner, the guide shaft 92 is inserted and passes through the pin holes 28a, 28b and the small end hole 30. The piston pin 32 is inserted into the pin holes 28a, 28b and the small end hole 30. Accordingly, the large end 14b of the connecting rod 14 can be moved along the large end retaining platform 112 such that the small end 14a of the connecting rod 14 moves along the piston pin 32.

[0130] Accordingly, the small end hole 30 and the pin holes 28a and 28b can be made coaxial, and the piston pin 32 can be inserted into the small end hole 30 and the pin holes 28a and 28b to assemble the piston 12 and the connecting rod 14.

[0131] As a result, by inserting the piston pin 32 into the small end hole 30 of the connecting rod 14 and the pin holes 28a and 28b of the piston 12, the small end hole 30 and the pin holes 28a and 28b of the piston 12 are made coaxial, thereby making it easy and stable to adjust the connecting rod 14 and the piston 12 to the specified position. Therefore, by inserting the piston pin 32 into the pin holes 28a and 28b and the small end hole 30, various pistons 12 and connecting rods 14 with different shapes can be reliably assembled.

[0132] The base 124 has a small end bearing member 118. The small end bearing member 118 is able to hold the lower surface of the small end 14a of the connecting rod 14. When the skirt 52 of the piston 12 is held by the second holding member 70 of the skirt holding mechanism 54, the connecting rod 14 can be movably held in a horizontal state by the small end bearing member 118, at which time the large end 14b of the connecting rod 14 is placed on the large end holding platform 112.

[0133] In the skirt retaining mechanism 54, the engaging portion 158 of the small end bearing member 118 engages with the receiving hole 88 of the second retaining member 70. Accordingly, when the second retaining member 70 moves toward the skirt 52 of the piston 12, the small end bearing member 118 moves in conjunction with the second retaining member 70 and moves integrally. Consequently, the bearing plate 156 of the small end bearing member 118 can move to a position facing the lower surface of the small end 14a of the connecting rod 14. As a result, the small end 14a can be held in a horizontal state by the bearing plate 156.

[0134] The above implementation methods are summarized as follows.

[0135] The above embodiment provides a piston and connecting rod assembly device (10) having a piston holding platform (24), a connecting rod holding platform (112), an intermediate holding part (116), and a piston pin insertion unit (34). The piston holding platform (24) has a lower end pin hole holding part (94) and a guide shaft (92). When the small end (14a) of the connecting rod (14) is inserted into the skirt (52) of the piston (12), and the axis of the pin hole (28a, 28b) of the piston facing the vertical direction is approximately aligned with the axis of the small end hole (30) of the small end, the lower end pin hole holding part (94) holds the lower end of the pin hole. The guide shaft (92) can move vertically relative to the lower end pin hole holding part and is aligned in a manner that passes through the pin hole and the small end hole. The connecting rod holding platform (112) is used to hold the large end (14a) of the connecting rod. 4b); The intermediate holding part (116) holds the intermediate part (114) between the small end and the large end of the connecting rod; The piston pin insertion unit (34) inserts the piston pin (32) from above when the small end hole and the pin hole are aligned. The piston and connecting rod assembly device (10) is characterized by having a piston holding unit (22) for holding the piston. The piston holding unit has a top surface holding mechanism (50), a skirt holding mechanism (54) and a movable mechanism (56), wherein the top surface holding mechanism (50) holds and fixes the top surface (48) of the piston; the skirt holding mechanism (54) holds and fixes the skirt (52) of the piston; and the movable mechanism (56) moves the top surface holding mechanism and the skirt holding mechanism to a fixed position for fixing the piston or an open position for releasing the piston from fixation.

[0136] The intermediate holding portion has a small end holding member (118) which holds the lower surface of the small end when the skirt is held by the skirt holding mechanism.

[0137] The skirt holding mechanism has an engagement mechanism (88) that engages with the small end holding member. When the skirt is held by moving the movable mechanism toward the skirt of the piston, the engagement mechanism causes the small end holding member to move toward the small end.

[0138] The process includes the following steps: a placement step, in which the small end of the connecting rod is inserted into the skirt of the piston, and the axis of the pin hole of the piston is approximately aligned with the axis of the small end hole of the small end, a guide shaft is inserted and passes through the lower end retaining part of the pin hole of the piston retaining platform, and the piston and the connecting rod are placed by the connecting rod retaining platform that places the large end of the connecting rod and the intermediate retaining part that holds the middle part of the connecting rod; a piston holding step, in which the piston is fixed by a piston holding unit; and a piston pin insertion step, in which the piston pin is inserted from above into the pin hole of the piston fixed in the piston holding step, the piston holding step consisting of the following steps: a top surface holding step, in which the piston is pressed and fixed by a top surface holding mechanism. The top surface and skirt holding process are performed approximately simultaneously with the top surface holding process. The skirt holding mechanism is inserted into the interior of the skirt of the piston and presses and fixes the piston in the opposite direction to the direction of pressing the top surface in the top surface holding process. The piston pin insertion process includes: an insertion process, in which the piston pin is inserted into the interior of the pin hole of the piston held in the piston holding process; an abutment process, in which the top end of the piston pin abuts against the upper end of the guide shaft; a pressing process, in which the guide shaft is pressed down into the interior of the lower end holding part of the pin hole while the top end of the piston pin abuts against the guide shaft; and a locking process, in which the upward movement of the guide shaft is locked at the position where the piston pin insertion is completed.

[0139] The piston holding process includes: an engagement process in which the small end holding member of the intermediate holding portion engages with the skirt holding mechanism, the intermediate holding portion holding the middle portion (114) between the small end and the large end of the connecting rod; and a process in which the small end holding member moves toward the small end to hold the small end as the skirt holding action is performed.

[0140] The piston holding unit is movable between an opposing position located above the piston holding platform and a clearance position that avoids the opposing position. The piston holding process includes: a piston holding unit moving process, which moves the piston holding unit from the clearance position to the opposing position; a holding preparation process, which positions the top surface holding mechanism and the skirt holding mechanism in opposing positions separated by the piston; and a process of fixing the top surface holding mechanism and the skirt holding mechanism to the piston by means of a movable mechanism, or releasing the fixed state so as not to contact the piston.

[0141] Furthermore, the present invention is not limited to the above-described embodiments, and various structures may be adopted without departing from the spirit of the present invention.

Claims

1. A piston and connecting rod assembly device (10) comprising a piston retaining platform (24), a connecting rod retaining platform (112), an intermediate retaining portion (116), and a piston pin insertion unit (34), wherein, The piston retainer (24) has a pin hole lower end retaining part (94) and a guide shaft (92). When the small end (14a) of the connecting rod (14) is inserted into the skirt (52) of the piston (12) and the axis of the pin hole (28a, 28b) of the piston facing the vertical direction is approximately aligned with the axis of the small end hole (30) of the small end, the pin hole lower end retaining part (94) retains the lower end of the pin hole, and the guide shaft (92) can move in and out in the vertical direction relative to the pin hole lower end retaining part and pass through the pin hole and the small end hole for alignment. The link holding platform (112) is used to hold the large end (14b) of the link. The intermediate retaining part (116) retains the intermediate part (114) between the small end and the large end of the connecting rod; The piston pin insertion unit (34) inserts the piston pin (32) from above when the small end hole and the pin hole are aligned. The piston and connecting rod assembly (10) is characterized in that, It has a piston holding unit (22) for holding the piston. The piston retaining unit is configured to maintain the attitude and position of the piston during the insertion of the piston pin into the pin hole. The piston holding unit has a top surface holding mechanism (50), a skirt holding mechanism (54), and a movable mechanism (56), wherein, The top surface retaining mechanism (50) presses and fixes the top surface (48) of the piston. The skirt holding mechanism (54) presses and fixes the skirt (52) of the piston from the opposite direction to the direction in which the top surface holding mechanism presses the piston. The movable mechanism (56) moves the top surface retaining mechanism and the skirt retaining mechanism to a fixed position that fixes the piston or to an open position that releases the piston from fixation.

2. The assembly apparatus for the piston and connecting rod according to claim 1, characterized in that, The intermediate holding portion has a small end holding member (118) that holds the lower surface of the small end when the skirt is held by the skirt holding mechanism.

3. The piston and connecting rod assembly device according to claim 2, characterized in that, The skirt retaining mechanism has an engaging mechanism (158) that engages with the small end retaining member. When the skirt is held in place by moving the movable mechanism toward the skirt of the piston, the engaging mechanism causes the small end holding member to move toward the small end.

4. A method for assembling a piston and a connecting rod, characterized in that, The device includes a mounting process in which, with the small end of the connecting rod inserted into the skirt of the piston and the axis of the pin hole of the piston approximately aligned with the axis of the small end hole of the small end, the lower end of the pin hole is held by the lower end holding part of the pin hole of the piston holding platform, the guide shaft is inserted and passes through the pin hole and the small end hole, and the piston and the connecting rod are mounted by the connecting rod holding platform for mounting the large end of the connecting rod and the intermediate holding part for holding the middle part of the connecting rod. The piston holding process involves fixing the piston using a piston holding unit; and In the piston pin insertion process, the piston pin is inserted from above into the pin hole of the piston, which has been fixed in the piston holding process. The piston holding process consists of the following steps: The top surface holding process involves pressing and fixing the top surface of the piston using a top surface holding mechanism; and The skirt holding process is performed approximately simultaneously with the top surface holding process. The skirt holding mechanism is inserted into the interior of the piston's skirt and presses and fixes the piston in a direction opposite to the direction of pressing the top surface in the top surface holding process. The piston pin insertion process includes: In the insertion process, the piston pin is inserted into the pin hole of the piston held in the piston holding process; The contact process involves bringing the top end of the piston pin into contact with the upper end of the guide shaft. In the pressing process, with the top end of the piston pin abutting against the guide shaft, the guide shaft is pressed down into the interior of the lower end retaining portion of the pin hole; and In the locking process, the upward movement of the guide shaft is locked at the position where the piston pin has been fully inserted. The piston holding process includes: an engagement process, in which the small end holding member of the intermediate holding portion engages with the skirt holding mechanism, the intermediate holding portion holding the intermediate portion (114) between the small end and the large end of the connecting rod; and The process of moving the small end holding member toward the small end to hold the small end during the holding action of the skirt.

5. A method for assembling a piston and a connecting rod, characterized in that, The device includes a mounting process in which, with the small end of the connecting rod inserted into the skirt of the piston and the axis of the pin hole of the piston approximately aligned with the axis of the small end hole of the small end, the lower end of the pin hole is held by the lower end holding part of the pin hole of the piston holding platform, the guide shaft is inserted and passes through the pin hole and the small end hole, and the piston and the connecting rod are mounted by the connecting rod holding platform for mounting the large end of the connecting rod and the intermediate holding part for holding the middle part of the connecting rod. The piston holding process involves fixing the piston using a piston holding unit; and In the piston pin insertion process, the piston pin is inserted from above into the pin hole of the piston, which has been fixed in the piston holding process. The piston holding process consists of the following steps: The top surface holding process involves pressing and fixing the top surface of the piston using a top surface holding mechanism; and The skirt holding process is performed approximately simultaneously with the top surface holding process. The skirt holding mechanism is inserted into the interior of the piston's skirt and presses and fixes the piston in a direction opposite to the direction of pressing the top surface in the top surface holding process. The piston pin insertion process includes: In the insertion process, the piston pin is inserted into the pin hole of the piston held in the piston holding process; The contact process involves bringing the top end of the piston pin into contact with the upper end of the guide shaft. In the pressing process, with the top end of the piston pin abutting against the guide shaft, the guide shaft is pressed down into the interior of the lower end retaining portion of the pin hole; and In the locking process, the upward movement of the guide shaft is locked at the position where the piston pin has been fully inserted. The piston holding unit is movable between an opposing position located above the piston holding platform and an avoidance position that avoids the opposing position. The piston holding process includes: The piston holding unit moving process moves the piston holding unit from the clearance position to the opposing position; In the preparation process, the top surface holding mechanism and the skirt holding mechanism are positioned opposite each other across the piston; and The process of fixing the top surface retaining mechanism and the skirt retaining mechanism to the piston by means of a movable mechanism, or releasing them from the fixed state by means of non-contact.

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