JP2008057567A - Engine piston assembling tool and engine piston assembling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately and surely conduct engine piston assembling operation in a short cycle time while simplifying an engine piston assembling device. <P>SOLUTION: A connecting rod 22 is supported so as to be rockable from an inclined posture in which a small end part 22s is arranged to be lifted slightly higher than a large end part 22b to a horizontal posture. The connecting rod 22 and a piston 28 are positioned with a small end hole 22hs and a piston pin hole 28h as references as a guide rod 16 is provided through both the small end hole 22hs of the connection rod 22 and the piston pin hole 28h of the piston 28 from a lower position to an upper position. As the guide rod 16 is lowered, the connecting rod 22 follows the guide rod 16 by friction between an inner circumference wall surface of the small end hole 22hs of the connecting rod 22 and an outer circumference wall surface of the guide rod 16 and the connecting rod 22 takes the horizontal posture and thus it is possible to smoothly insert the piston pin 30 to the small end hole 22hs. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an engine piston assembling jig and an engine piston assembling method for connecting an engine piston and a connecting rod with a piston pin.

  Conventionally, as a method of assembling the engine piston, the connecting rod is supported in a horizontal posture, the piston is placed on the small end portion of the connecting rod, the small end hole of the connecting rod is aligned with the piston pin hole of the piston, and the piston is inserted into the piston pin hole. A technique of inserting a pin is common, and various automatic assembly apparatuses have been developed. As an example, with the center position and axial direction of the small end hole of the connecting rod and the piston pin hole of the piston exactly aligned on the pallet, and the piston and connecting rod set, the entire pallet is loaded into the engine piston assembly device. , A device for automatically inserting a piston pin (for example, refer to Patent Document 1), and after setting the connecting rod on a pallet that can be moved up and down, put the piston on the small end of the connecting rod, A device (for example, refer to Patent Document 2) that inserts a piston pin into the piston pin hole from above the piston by accurately matching the center position and the axial direction of the piston pin hole of the piston.

JP-A-6-190663 Japanese Patent Laid-Open No. 11-285927

By the way, generally, since the connecting rod is a forged product and the piston is a cast product, the surface of the component is relatively rough, and it is difficult to accurately position both of them. However, the above-described conventional piston assembly apparatus needs to have an apparatus structure for securely fixing the connecting rod and the piston by accurately matching the center position and the axial direction of the small end hole of the connecting rod and the piston pin hole of the piston. Therefore, it has been difficult to avoid the need for complicated and high-precision apparatus structure.
The present invention has been made in view of the above problems, and its object is to facilitate the simplification of the engine piston assembling apparatus and perform the engine piston assembling work accurately and reliably with a short cycle time. It is possible to do in.

In order to solve the above problems, the engine piston assembling jig of the present invention has a connecting rod support portion, a piston support portion, a guide rod, and a guide rod inserted into the small end hole and the piston pin hole of the connecting rod. And a guide rod holding means for holding. Then, the piston and the connecting rod are caused to follow the piston pin or the guide rod in a state where the connecting rod is swingably held in the connecting rod supporting portion without positioning with high accuracy with respect to the piston supported by the piston supporting portion. Thus, the center position and the axial direction of the small end hole of the connecting rod and the piston pin hole of the piston are accurately matched, and the connecting rod assembly work is performed smoothly and reliably.
In order to solve the above problems, the engine piston assembling method of the present invention is directed so that the axial center of the small end hole of the connecting rod is oriented in a substantially vertical direction, and the small end is slightly higher than the large end. The connecting rod is supported so that it can swing from the tilted position raised to the horizontal position (that is, the connecting rod is intentionally supported so as to be able to swing), and the piston is put on the small end of the connecting rod. A guide rod with an outer diameter formed within the tolerance range swung in the small diameter direction with respect to the outer diameter of the pin passes through both the small end hole of the connecting rod and the piston pin hole of the piston from below to above. After the connecting rod and piston are temporarily assembled, the piston pin is inserted into the piston pin hole, so that the center position and the axial direction of the connecting pin and piston pin hole are accurately matched. And performs rod assembly work smoothly and reliably.

(Aspect of the Invention)
The following aspects of the present invention exemplify the configuration of the present invention, and will be described separately for easy understanding of various configurations of the present invention. Each item does not limit the technical scope of the present invention. Therefore, the technical aspects of the present invention also apply to those in which some of the constituent elements in each section are replaced, deleted, or other constituent elements are added while taking into account the best mode for carrying out the invention. It can be included in the range.

(1) The shaft center of the small end hole of the connecting rod is oriented substantially in the vertical direction, and can be swung from an inclined posture in which the small end portion is lifted slightly higher than the large end portion to a horizontal posture. The connecting rod supporting portion for supporting the connecting rod and the small end portion of the connecting rod supported by the connecting rod supporting portion are covered with a piston with the axial center of the piston pin hole directed in a substantially vertical direction. An engine piston assembling jig comprising a piston support portion for supporting the piston in a state where the axial centers of the end holes are substantially coincident.
The engine piston assembling jig described in this section has an inclination in which the shaft center of the small end hole of the connecting rod is directed in a substantially vertical direction by the connecting rod support portion, and the small end portion is lifted slightly higher than the large end portion. With the connecting rod supported so that it can swing from the posture to the horizontal posture, the piston pin hole axial center is directed substantially vertically to the small end of the connecting rod supported by the connecting rod support. Put on. Then, the piston is supported by the piston support portion in a state in which the piston pin hole and the small end hole of the connecting rod substantially match (that is, in a state where they do not completely match). In this state, when the piston pin is inserted into the piston pin hole, when the piston pin passes through the small end hole of the connecting rod, the connecting rod is caused by friction between the inner peripheral wall surface of the small end hole of the connecting rod and the outer peripheral wall surface of the piston pin. Following the piston pin, the small end portion rotates downward from the inclined posture in which the small end portion is lifted slightly higher than the large end portion, and becomes a horizontal posture. As a result, the axial center of the small end hole of the connecting rod coincides with the axial center of the piston pin, and the insertion of the piston pin into the piston pin hole of the piston and the insertion of the piston pin into the small end hole of the connecting rod are completed.

(2) In the above item (1), it penetrates from below to above both the small end hole of the connecting rod supported by the connecting rod support part and the piston pin hole of the piston positioned by the piston support part. A guide that has a large diameter portion that is long enough to have a large diameter formed within a tolerance range in which the outer diameter of the cylindrical piston pin is swung in a small diameter direction with respect to the outer diameter of the cylindrical piston pin. An engine piston assembling jig comprising a rod.
The engine piston assembling jig described in this section is the engine assembling jig described in (1), wherein the guide rod is moved from below to above with respect to both the small end hole of the connecting rod and the piston pin hole of the piston. By passing through, the connecting rod and the piston are temporarily assembled in a state where the connecting rod and the piston are positioned with reference to the small end hole and the piston pin hole. Since the outer diameter of the guide rod is formed within the tolerance range swung in the small diameter direction with respect to the outer diameter of the cylindrical piston pin, the piston pin hole and piston pin have an interference fit. The relationship between the pin hole and the guide rod is a clearance fit, and the guide rod is smoothly inserted into the piston pin hole. On the other hand, since the relationship between the small end hole of the connecting rod and the piston pin is originally a clearance fit, the relationship between the small end hole of the connecting rod and the guide rod is naturally a clearance fit, and the guide rod is a small size of the connecting rod. It is smoothly inserted into the end hole.
And when inserting the piston pin into the piston pin hole, if the guide rod is lowered, the guide rod passes through the small end hole of the connecting rod, and the inner peripheral wall surface of the small end hole of the connecting rod and the guide rod Due to the friction with the outer peripheral wall, the connecting rod follows the guide rod, and the small end rotates downward from the inclined position where the small end is lifted slightly higher than the large end. The axial center of the end hole is aligned with the axial center of the piston pin. Therefore, if the piston pin is passed through the small end hole of the connecting rod following the guide rod, the axial center of the small end hole of the connecting rod and the axial center of the piston pin are already aligned at that time. Therefore, it is possible to smoothly insert the piston pin into the small end hole of the connecting rod.

(3) The engine piston assembling jig according to the above item (2), which has a small-diameter portion that protrudes from the tip of the large-diameter portion of the guide rod and has an outer diameter that can be fitted to the inner diameter hole of the piston pin.
The engine piston assembly jig described in this section is used when the piston pin is inserted into the piston pin hole by fitting the inner diameter hole of the piston pin into the small diameter portion protruding from the tip of the large diameter portion of the guide rod. The positioning is surely performed by the guide rod.

(4) In the above item (2) or (3), the large diameter portion of the guide rod penetrates both the small end hole of the connecting rod and the piston pin hole of the piston, and a piston is formed on the upper end surface of the large diameter portion. An engine piston assembling jig comprising guide rod holding means for holding the guide rod at a position where one end of the pin can be contacted and lowering the guide rod as the piston pin is inserted.
In the engine piston assembling jig described in this section, the guide rod is passed through both the small end hole of the connecting rod and the piston pin hole of the piston from the lower side to the upper side. By holding the guide rod with the guide rod holding means with the pin hole temporarily assembled, the piston pin can be securely set on the guide rod as preparation work for piston pin insertion work. It is. Further, since the guide rod holding means lowers the guide rod as the piston pin is inserted, the guide rod and the piston pin are in close contact with each other while the piston pin passes through the small end hole of the connecting rod following the guide rod. Is maintained, and the piston pin can be smoothly inserted into the small end hole of the connecting rod.

  (5) The axial center of the small end hole of the connecting rod is oriented substantially vertically, and can swing from a tilted posture in which the small end portion is lifted slightly higher than the large end portion to a horizontal posture. The connecting rod supporting portion that supports the two positions of the large end portion and the intermediate portion of the connecting rod and the small end portion of the connecting rod supported by the connecting rod supporting portion with the axial center of the piston pin hole directed substantially vertically The piston pin hole and the small end hole of the connecting rod are substantially aligned with each other, and the piston supporting part for supporting the piston, the small end hole of the connecting rod supported by the connecting rod supporting part, and the piston supporting part Both of the piston pin holes of the piston positioned on the side have a length that penetrates from the bottom to the top, and the outer diameter is smaller than the outer diameter of the cylindrical piston pin. Shaken A guide rod that can be moved up and down, having a large diameter portion formed within a tolerance range, and a small diameter portion that protrudes from the tip of the large diameter portion and that has an outer diameter that can be fitted into the inner diameter hole of the piston pin. And the large diameter portion of the guide rod passes through both the small end hole of the connecting rod and the piston pin hole of the piston, and the end of the piston pin is in contact with the upper end surface of the large diameter portion. An engine piston assembling jig comprising a guide rod holding means for holding the guide rod and lowering the guide rod as the piston pin is inserted.

The engine piston assembling jig described in this section is configured so that the connecting rod support portion that supports the large end portion and the intermediate portion of the connecting rod has the axial center of the small end hole of the connecting rod oriented in a substantially vertical direction, Piston is connected to the small end of the connecting rod supported by the connecting rod support in a state where the connecting rod is supported so that the small end can be swung from a tilted position to a horizontal position. Place the piston so that the axial center of the pin hole faces in a substantially vertical direction. Then, the guide rod is passed through both the small end hole of the connecting rod and the piston pin hole of the piston from below to above, so that the connecting rod and the piston are positioned with reference to the small end hole and the piston pin hole. Temporarily assembled in the state that has been done. Since the outer diameter of the guide rod is formed within the tolerance range swung in the small diameter direction with respect to the outer diameter of the cylindrical piston pin, the piston pin hole and piston pin have an interference fit. The relationship between the pin hole and the guide rod is a clearance fit, and the guide rod is smoothly inserted into the piston pin hole. On the other hand, since the relationship between the small end hole of the connecting rod and the piston pin is originally a clearance fit, the relationship between the small end hole of the connecting rod and the guide rod is naturally a clearance fit, and the guide rod is a small size of the connecting rod. It is smoothly inserted into the end hole. Then, the connecting rod and the piston are positioned in a state in which the piston pin hole and the small end hole of the connecting rod are approximately matched (that is, not completely matched).
Then, by fitting the inner diameter hole of the piston pin to the small diameter part protruding from the tip of the large diameter part of the guide rod, the guide rod is surely aligned when the piston pin is inserted into the piston pin hole. .
Moreover, by holding the guide rod by the guide rod holding means, the piston pin can be reliably set on the guide rod as preparation work for the piston pin insertion operation without causing the guide rod to inadvertently descend. .
And when inserting the piston pin into the piston pin hole, if the guide rod is lowered, the connecting rod follows the guide rod due to friction between the inner peripheral wall surface of the small end hole of the connecting rod and the outer peripheral wall surface of the guide rod, The small end rotates slightly downward from the tilted position with the small end lifted slightly higher than the large end, and the horizontal position is obtained by rotating the small end downward, and the axis of the small end hole of the connecting rod coincides with the axis of the piston pin. It becomes a state. Therefore, while the piston pin passes through the small end hole of the connecting rod following the guide rod, the axial center of the small end hole of the connecting rod coincides with the axial center of the piston pin. It is possible to smoothly insert the piston pin into the hole.
At this time, since the guide rod holding means lowers the guide rod as the piston pin is inserted, the guide rod and the piston pin are brought into close contact with each other when the piston pin passes through the small end hole of the connecting rod following the guide rod. The state is maintained, and the piston pin can be smoothly inserted into the small end hole of the connecting rod.

Note that the piston support part is, for example, a piston receiver having a recess that follows the outer shape of the piston. By placing the piston on the piston receiver, the piston and the axis of the piston pin hole are substantially vertical. It covers the small end portion of the connecting rod toward the direction, and securely holds the posture in which the piston pin hole and the small end hole of the connecting rod substantially coincide with each other.
In addition, for example, a ball plunger (a ball-shaped contactor that is rotatably pressed against the side surface of the guide rod by a spring) is used as the guide rod holding means.

(6) The connecting rod support portion includes a first connecting rod receiver that supports the intermediate portion of the connecting rod at a position closer to the small end than the center of gravity of the connecting rod, and a second connecting rod receiver that supports the large end of the connecting rod. And an engine piston assembly jig (claim 2).
The engine piston assembly jig described in this section places the center of gravity of the connecting rod between the first connecting rod receiver and the second connecting rod receiver, and supports the connecting rod by the first and second connecting rod receivers. The connecting rod is stably held on the first and second connecting rod receivers. Also, since the connecting rod is held in a state where it is supported on the first and second connecting rod receivers, for example, simply placed, the connecting rod is small when the guide rod rod is lowered. Due to the friction between the inner peripheral wall surface of the end hole and the outer peripheral wall surface of the guide rod, the connecting rod follows the guide rod, and the first connecting rod receiver is in an inclined position in which the small end portion is lifted slightly higher than the large end portion. Starting from gold, it is possible to rotate the small end downward to achieve a horizontal posture. At this time, the large end of the connecting rod floats up from the second connecting rod receiver, and the rotation of the connecting rod is not hindered.
The first connecting rod receiver has a recess that follows the outer shape of the intermediate portion of the connecting rod, and the second connecting rod receiver has a recess that follows the outer shape of the large end of the connecting rod. By simply placing the connecting rod on the second connecting rod receiver, the connecting rod is securely held.

(7) An engine piston assembling jig in which the connecting rod support portion, the piston support portion, the guide rod, and the guide rod holding means are provided on one pallet.
The engine piston assembling jig described in this section is to temporarily connect the connecting rod and piston on the pallet, insert the piston pin into the small end hole of the connecting rod and the piston pin hole of the piston, The connecting rod and piston that have been assembled are transported together with the pallet. That is, by connecting the connecting rod and the piston together with the pallet by a conveyor means such as a conveyor and a robot arm, on the engine piston assembling line, the conveying work before assembling each part, assembling work, and after assembling. It becomes possible to carry out the transfer work smoothly in units of pallets.

  (8) The axial center of the small end hole of the connecting rod is oriented substantially in the vertical direction, and can be swung from an inclined posture in which the small end portion is lifted slightly higher than the large end portion to a horizontal posture. The connecting rod is supported, and the small end of the connecting rod is covered with the piston with the axial center of the piston pin hole in the substantially vertical direction, and the outer diameter is within the tolerance range swung in the small diameter direction with respect to the outer diameter of the piston pin. The guide rod formed with is penetrated from both the small end hole of the connecting rod and the piston pin hole of the piston from the bottom to the top, and the piston pin hole and the small end hole of the connecting rod are approximately aligned. An engine piston assembling method for positioning the connecting rod and the piston and inserting the piston pin into the piston pin hole by pushing down the guide rod with the piston pin.

The engine piston assembling method described in this section is a horizontal posture from an inclined posture in which the shaft center of the small end hole of the connecting rod is oriented substantially in the vertical direction and the small end portion is lifted slightly higher than the large end portion. In a state where the connecting rod is supported so that the connecting rod is supported, the small end portion of the connecting rod supported by the connecting rod support portion covers the piston with the axial center of the piston pin hole directed in a substantially vertical direction.
Then, the guide rod is passed through both the small end hole of the connecting rod and the piston pin hole of the piston from below to above, so that the connecting rod and the piston are positioned with reference to the small end hole and the piston pin hole. Temporarily assembled in the state that has been done. Since the outer diameter of the guide rod is formed within the tolerance range swung in the small diameter direction with respect to the outer diameter of the cylindrical piston pin, the piston pin hole and piston pin have an interference fit. The relationship between the pin hole and the guide rod is a clearance fit, and the guide rod is smoothly inserted into the piston pin hole. On the other hand, since the relationship between the small end hole of the connecting rod and the piston pin is originally a clearance fit, the relationship between the small end hole of the connecting rod and the guide rod is naturally a clearance fit, and the guide rod is a small size of the connecting rod. It is smoothly inserted into the end hole. Then, the connecting rod and the piston are positioned in a state in which the piston pin hole and the small end hole of the connecting rod are approximately matched (that is, not completely matched).
When the piston pin is inserted into the piston pin hole while pushing down the guide rod with the piston pin, the connecting rod follows the guide rod due to friction between the inner peripheral wall surface of the small end hole of the connecting rod and the outer peripheral wall surface of the guide rod. The small end rotates downward from the inclined position where the small end is lifted slightly higher than the large end, resulting in a horizontal position, and the axial center of the small end hole of the connecting rod coincides with the axial center of the piston pin. It will be in the state. Therefore, while the piston pin passes through the small end hole of the connecting rod following the guide rod, the axial center of the small end hole of the connecting rod and the axial center of the piston pin are already aligned, and the piston pin with respect to the small end hole of the connecting rod Can be smoothly inserted.

  Since this invention was comprised in this way, it becomes possible to perform an engine piston assembly | attachment operation | work correctly and reliably with a short cycle time, and can facilitate simplification of an engine piston assembly apparatus.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the part which is the same as that of a prior art, or an equivalent part, and detailed description is abbreviate | omitted.
As shown in FIGS. 1 to 4, the engine piston assembly jig 10 according to the embodiment of the present invention includes a connecting rod support portion 12, a piston support portion 14, a guide rod 16, and a guide rod holding means 18. Are provided on one pallet 20. In the illustrated example, two sets of connecting rod support portion 12, piston support portion 14, guide rod 16, and guide rod holding means 18 are provided for one pallet 20, and two sets of piston sets are provided. Attached work can be performed simultaneously.

  The connecting rod support portion 12 has an inclined posture in which the axial center of the small end hole 22hs (FIG. 4) of the connecting rod 22 is oriented in a substantially vertical direction, and the small end portion 22s is lifted slightly higher than the large end portion 22b. The small end portion 22s swings downward and supports the two positions of the connecting rod large end portion 22b and the intermediate portion 22m so as to have a horizontal posture. Here, the connecting rod support portion 12 includes a first connecting rod receiver 12A and a second connecting rod receiver 12B. The first connecting rod receiver 12A is closer to the small end portion 22s than the position of the center of gravity 22g of the connecting rod (as shown in FIG. 4, it is generally located at the portion that transitions from the intermediate portion 22m to the large end portion 22b). The second connecting rod receiver 12B supports the large end 22b of the connecting rod.

  In the illustrated example, the first connecting rod receiver 12A is fixed to the piston support portion 14 and has a receiving surface that follows the intermediate portion 22m of the connecting rod. Further, the second connecting rod receiver 12B includes a mounting table 26 supported by a column 24 standing on the pallet 20, and the mounting table 26 engages with a large end hole 22hb of a large end portion 22b of the connecting rod. A protrusion 26a is formed. The height of the mounting table 26 is such that when the connecting rod 22 is leveled by placing the connecting rod intermediate portion 22m on the connecting rod receiver 12A, the large end 22b of the connecting rod is slightly (about 1 mm) with respect to the mounting table 26. It is a floating height. Therefore, when the intermediate portion 22m of the connecting rod is placed on the connecting rod receiver 12A and the large end portion 22b is brought into contact with the mounting table 26, the inclined posture is such that the small end portion 22s is slightly raised to the large end portion 22b. .

  The piston support portion 14 covers the piston 28 on the small end portion 22s of the connecting rod 22 supported by the connecting rod support portion 12 with the axis of the piston pin hole 28h of the piston 28 directed in a substantially vertical direction, and the piston pin hole 28h. The piston 28 is positioned in a state in which the connecting rod and the small end hole 22hs of the connecting rod substantially coincide with each other. The piston support portion 14 has a block shape, and the upper surface thereof is formed in a concavo-convex shape following the shape of the side surface of the piston 28, and the piston 28 can be stably held only by placing the piston 28.

  The guide rod 16 is provided on the piston support portion 14 and can be moved up and down with respect to the piston support portion 14. The guide rod 16 has a large diameter portion 16b and a small diameter portion 16s. The large diameter portion 16b penetrates both the small end hole 22hs of the connecting rod 22 supported by the connecting rod support portion 12 and the piston pin hole 28h of the piston 28 positioned in the piston support portion 14 from the lower side to the upper side. The outer diameter of the cylindrical piston pin 30 is within a tolerance range that is swung in the small diameter direction with respect to the outer diameter of the cylindrical piston pin 30. The small-diameter portion 16s protrudes from the tip of the large-diameter portion 16b and is formed so that its outer diameter can be fitted into the inner-diameter hole 30h of the piston pin 30. Note that a guide groove 16d (see FIG. 3) is provided in the longitudinal direction on the side surface of the large-diameter portion 16b to increase the operation accuracy when the guide rod 16 is raised and lowered. Moreover, since the cylindrical guide 17 (refer FIG. 4) which slide-guides the guide rod 16 is open | released below, the lower end part of the guide rod 16 can be pushed up from the downward direction. The guide rod 16 can be pushed up manually or automatically.

  In the guide rod holding means 18, the large diameter portion 16b of the guide rod 16 penetrates both the small end hole 22hs of the connecting rod 22 and the piston pin hole 28h of the piston 28, and the piston pin 30 is formed on the upper end surface of the large diameter portion 16b. The guide rod 16 is held at a position where one end can be contacted (see FIG. 4), and the guide rod 16 is lowered as the piston pin 30 is inserted. In the embodiment of the present invention, a flat surface portion 16f (shown by a dotted line in FIG. 4) is formed on the side surface of the large diameter portion 16b of the guide rod 16, and a ball plunger that contacts the flat surface portion 16f is used. The flat portion 16f of the guide rod 16 is formed so as to become shallower toward the upper side (for this reason, it appears as an isosceles triangle in a side view), and as the guide rod 16 moves up, the ball plunger This increases the amount of immersion of the ball-shaped contact. Therefore, as the guide rod 16 is lowered, the force required to lower the guide rod 16 is reduced.

  As shown in FIGS. 5 to 7, the pallet 20 is circulated by a conveyor 32 constituting an engine piston assembly line. In the illustrated example, the pallet 20 is formed by cutting a metal plate into a necessary shape. Is. And it moves on the conveyor 32 when the engagement nail | claw 33 of the conveyor shown by FIG. 3 contact | abuts.

Subsequently, an engine piston assembly procedure using the engine piston assembly jig 10 will be described with reference to FIGS.
As shown in FIGS. 5 and 6, the pallet 20 of the engine piston assembly jig 10 is circulated by a conveyor 32 constituting an engine piston assembly line. An engine piston assembly device 34 is disposed on the path of the conveyor 32. The engine piston assembly device 34 includes an assembly tool 36 that applies pressure to the piston pin 30 from above, an actuator 38 (air cylinder) that drives the assembly tool 36 up and down, and a position confirmation sensor 40 for the assembly tool 36. Is provided. The engine piston assembly tool 34 is fixed to the lower end of an insertion rod 44 that is supported by a bearing 42 so as to be swingable up and down. The upper end of the insertion rod 44 is pivotally attached to an arm 46 that swings up and down. ing. Two sets of the assembly tool 36 and the insertion rod 44 are provided, and two sets of engine pistons can be simultaneously performed. In the illustrated example, the position confirmation sensor 40 indirectly detects the position of the assembly tool 36 by detecting the position of the actuator 38. The engine piston assembling device 34 assembles the actuator 38 (air cylinder) and the position confirmation sensor 40 to an existing device that manually operates a handle 48 provided on the arm 46 to insert the piston pin 30. Thus, it is configured as a low-cost automatic machine. Of course, a dedicated automatic engine assembling apparatus can also be used.

First, the connecting rod 22 is set on the connecting rod support portion 12 and the piston 28 is set on the piston support portion 14 of the engine piston assembling jig 10 at a place removed from the engine piston assembling device 34, respectively. At this time, the guide rod 16 of the engine piston assembling jig 10 is lifted to the ascending position by manual operation or using some actuator, and the guide rod 16 is pulled into the small end hole of the connecting rod 22 and the piston pin hole 28h of the piston 28. For both sides, the guide rod 16 is penetrated from below to above.
Then, the engine piston assembling jig 10 in which the connecting rod 22 and the piston 28 are set is moved to the insertion work position of the engine piston assembling device 34 by the conveyor 32. An operator fits the inner diameter hole 30 h of the piston pin 30 into the small diameter portion 16 s of the guide rod 16 using manual work or a feeder. At this time, if necessary, a lubricant is applied to the piston 30 or the piston pin hole 28h. Then, the assembly tool 36 is aligned with the piston pin 30 manually. Thereafter, the actuator 38 is operated to apply pressure from the assembly tool 36 to the piston pin 30, and the piston pin 30 is inserted into the piston pin hole 28 h of the piston 28.
When the piston pin insertion operation is completed, the engine piston assembly jig 10 for which the insertion operation has been completed is sent first by the conveyor 32, and the engine piston assembly jig 10 for which the subsequent insertion operation has not been completed is transmitted to the engine piston assembly. It moves to the insertion work position of the attaching device 34 and repeats the above work.

According to the embodiment of the present invention configured as described above, the following operational effects can be obtained.
That is, when the engine piston assembling work is performed using the engine piston assembling jig 10, the connecting rod support portion 12 that supports the two portions of the large end portion 22 b and the intermediate portion 22 m of the connecting rod 22 is used to connect the connecting rod 22. The connecting rod 22 is pivoted so that the axis of the small end hole 22hs is substantially vertically oriented and the small end 22s can be swung from a tilted position slightly elevated to a horizontal position with respect to the large end 22b. To support. Subsequently, the piston 28 is put on the small end portion 22 s of the connecting rod 22 supported by the connecting rod support portion 12 with the axis of the piston pin hole 28 h directed in a substantially vertical direction. At this time, the guide rod 16 penetrates both the small end hole 22hs of the connecting rod 22 and the piston pin hole 28h of the piston 28 from the lower side to the upper side, so that the connecting rod 22 and the piston 28 have the small end hole 22hs. And it will be in the state temporarily assembled in the state positioned on the basis of piston pin hole 28h. Since the outer diameter of the guide rod 16 is formed within a tolerance range that is swung in the small diameter direction with respect to the outer diameter of the cylindrical piston pin 30, it is an interference fit in the relationship between the piston pin hole 28 h and the piston pin 30. As a result, the gap between the piston pin hole 28h and the guide rod 16 is fitted. Therefore, the guide rod 16 is smoothly inserted into the piston pin hole 28h. On the other hand, since the relationship between the small end hole 22hs of the connecting rod 22 and the piston pin 30 is originally a clearance fit, the relationship between the small end hole hs of the connecting rod 22 and the guide rod 16 is naturally a clearance fit. Become. Therefore, the guide rod 16 is smoothly inserted into the small end hole 22hs of the connecting rod 22. Then, the connecting rod 22 and the piston 28 are positioned in a state where the small end hole 22hs and the piston pin hole 28h are substantially coincident (that is, not completely coincident).
The piston pin 30 is inserted into the piston pin hole 28h of the piston 28 by fitting the inner diameter hole 30h of the piston pin 30 to the small diameter portion 16s protruding from the tip of the large diameter portion 16b of the guide rod 16. Positioning is reliably performed by the guide rod 16. Moreover, by holding the guide rod 16 by the guide rod holding means 18, the piston pin 30 can be reliably set on the guide rod 16 without the guide rod 16 being inadvertently lowered.
Thus, since it is not necessary to completely position the connecting rod 22 and the piston 28 with the connecting rod support portion 12 and the piston support portion 14 until the piston pin 30 is inserted, the engine piston assembling jig 10 Each component does not require high precision, and the configuration of the engine piston assembly jig 10 can be simplified.

When the guide rod 16 is lowered when the piston pin 30 is inserted into the piston pin hole 28h, the connecting rod 22 is caused by friction between the inner peripheral wall surface of the small end hole 22hs of the connecting rod 22 and the outer peripheral wall surface of the guide rod 16. Following the guide rod 16, the small end 22 s rotates downward from the inclined posture in which the small end 22 s is slightly raised with respect to the large end 22 b to become a horizontal posture. Then, the axial center of the small end hole 22hs of the connecting rod 22 and the axial center of the piston pin 30 coincide with each other. Therefore, while the piston pin 30 passes through the small end hole 22hs of the connecting rod 22 following the guide rod 16, the axial center of the small end hole 22hs of the connecting rod 22 and the axial center of the piston pin 30 are in alignment. Thus, the piston pin 30 can be smoothly inserted into the small end hole 22hs of the connecting rod 22.
In addition, since the guide rod holding means 18 lowers the guide rod as the piston pin 30 is inserted, when the piston pin 30 passes through the small end hole 22hs of the connecting rod 22 following the guide rod 16, the guide rod 16 and the piston pin 30 are kept in close contact with each other, and the piston pin 30 can be smoothly inserted into the small end hole 22hs of the connecting rod 22.

  Also, the connecting rod 22 is placed between the first connecting rod receiver 12A and the second connecting rod receiver 12B (see FIG. 4), and the connecting rod 11 is connected to the connecting rod 11 by the first and second connecting rod receivers 12A and 12B. The connecting rod 22 is stably held on the first and second connecting rod receivers 12A and 12B. Further, since the connecting rod 22 is held on the first and second connecting rod receivers 12A and 12B, that is, simply placed, it is held when the guide rod 16 is lowered. The connecting rod 22 follows the guide rod 16 due to friction between the inner peripheral wall surface of the small end hole 22hs of the connecting rod 22 and the outer peripheral wall surface of the guide rod 16, and the small end portion 22s is slightly higher than the large end portion 22b. From the tilted posture, the small end 22s rotates downward from the first connecting rod receiver 12A as a starting point. At this time, the large end portion 22b of the connecting rod is lifted from the second connecting rod receiver 12B, and the rotation of the connecting rod 22 is not hindered.

  Further, since the connecting rod support portion 12, the piston supporting portion 14, the guide rod 16, and the guide rod holding means 18 are provided on one pallet 20, the connecting rod 22 and the piston 28 are temporarily mounted on the pallet 20. The assembled state is established by inserting the piston pin 30 into the small end hole 22hs of the connecting rod 22 and the piston pin hole 28h of the piston 28, and the connected connecting rod 22 and piston 28 are assembled together with the pallet 20. It is to be transported. Accordingly, the connecting rod 22 and the piston 28 together with the pallet 20 are conveyed by conveying means such as a conveyor 32 and a robot arm, so that the conveying work to the assembling device for the connecting rod 22 and the piston 28 on the engine piston assembling line. It is possible to smoothly perform the assembling work and the conveying work from the assembling apparatus after assembling in units of pallets 20.

It is the perspective view which showed the engine piston assembly jig | tool which concerns on embodiment of this invention in the partial cross section. It is a top view of the engine piston assembly jig which concerns on embodiment of this invention. It is AA sectional drawing of FIG. FIG. 3 is a view as viewed from the arrow B in FIG. 2 and is a partial cross-sectional view. It is a side view of the engine piston assembling apparatus according to the present invention. It is a front view of the engine piston assembling apparatus according to the present invention. It is a principal part enlarged view of FIG.

Explanation of symbols

10: Engine piston assembly jig, 12: Connecting rod support part, 14: Piston support part, 16: Guide rod, 16b: Large diameter part, 16s: Small diameter part, 18: Guide rod holding means, 20: Pallet, 22: Connecting rod, 22b: Large end of connecting rod, 22g: Center of gravity of connecting rod, 22hs: Small end hole of connecting rod, 22m: Intermediate portion of connecting rod, 22s: Small end of connecting rod, 28: Piston, 28h: Piston pin hole, 30 : Piston pin, 30h: inner diameter hole, 34: engine piston assembly device

Claims (4)

Connect the connecting rod so that the shaft center of the small end hole of the connecting rod is oriented in a substantially vertical direction and can be swung from a tilted position in which the small end is lifted slightly higher than the large end to a horizontal position. A connecting rod support that supports two locations, the large end and the middle,
The small end of the connecting rod supported by the connecting rod support is covered with a piston with the axial center of the piston pin hole directed in a substantially vertical direction, and the axial center of the piston pin hole and the small end hole of the connecting rod are approximately aligned. A piston support for positioning the piston;
Both the small end hole of the connecting rod supported by the connecting rod support part and the piston pin hole of the piston positioned by the piston support part have a length that penetrates from below to above, and A large-diameter portion formed within a tolerance range in which the outer diameter is swung in the small-diameter direction with respect to the outer diameter of the cylindrical piston pin, and the outer diameter projecting from the tip of the large-diameter portion is an inner diameter hole of the piston pin. And a guide rod that can be moved up and down,
The guide rod is located at a position where the large diameter portion of the guide rod passes through both the small end hole of the connecting rod and the piston pin hole of the piston, and one end of the piston pin can contact the upper end surface of the large diameter portion. And a guide rod holding means for lowering the guide rod in accordance with the progress of insertion of the piston pin. The connecting rod support portion includes a first connecting rod receiver that supports the intermediate portion of the connecting rod at a position closer to the small end than the center of gravity of the connecting rod, and a second connecting rod receiver that supports the large end of the connecting rod. The engine piston assembling jig according to claim 1, wherein: The engine piston assembly treatment according to claim 1 or 2, wherein the connecting rod support portion, the piston support portion, the guide rod, and the guide rod holding means are provided on one pallet. Ingredients. Connect the connecting rod so that the axial center of the small end hole of the connecting rod is oriented in a substantially vertical direction and swings from a tilted position with the small end raised slightly higher than the large end to a horizontal position. Support,
A guide rod whose outer diameter is formed within a tolerance range that is swung in the small diameter direction with respect to the outer diameter of the piston pin, with the small rod end of the connecting rod covering the piston with the axial center of the piston pin hole in the substantially vertical direction. Is inserted through both the small end hole of the connecting rod and the piston pin hole of the piston from the bottom to the top, and the connecting rod and the piston are positioned with the piston pin hole and the small end hole of the connecting rod approximately matching each other. And
An engine piston assembling method, wherein the piston pin is inserted into a piston pin hole so as to push down the guide rod with a piston pin.

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