Assembly device

Abstract

To assemble a valve into a valve guide hole without requiring special sensors or mechanisms.SOLUTION: In the present invention, a multi-joint robot 100 performs a probing operation of moving an exhaust valve V1 or intake valve V2 in a horizontal direction so as to naturally drop the exhaust valve or intake valve at a time point when positions align with valve guide holes h1, h2 on upper surfaces of the valve guide holes of a cylinder head cy held by a tilting device 300 in a state where the gripping force is released so as to prevent the exhaust valve or intake valve from falling over.SELECTED DRAWING: Figure 15

Description

Technical Field

[0001] The present invention relates to a valve incorporating device for a cylinder head.

Background Art

[0002] Conventionally, there is a technique of using a device to assemble a valve stem into a valve guide hole of a valve system of a cylinder head that is assembled manually. In Patent Document 1, as centering means for centering the tip of the intake and exhaust valve stem and the valve guide hole, a vacuum nozzle that moves below the valve guide hole and sucks outside air, and a negative pressure switch that detects the pressure in the pipe from the tip of the vacuum nozzle to the vacuum pump are provided. Centering is performed by sucking with the vacuum nozzle when the valve approaches above the valve guide hole.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the device of Patent Document 1 includes a vacuum nozzle, a negative pressure switch, etc., if dust is sucked during assembly or assembly oil used in other processes is sucked, the nozzle becomes clogged and suction cannot be performed, resulting in the problem that centering cannot be performed.

[0005] An object of the present invention is to provide a valve incorporating device for a cylinder head that can assemble a valve into a valve guide hole without having special sensors or mechanisms.

Means for Solving the Problems

[0006] One aspect of the present invention is an incorporation device for incorporating an exhaust valve or an intake valve into a cylinder head, which includes a rotary holding part and an articulated robot. The rotary holding part rotatably holds the cylinder head. The articulated robot has a gripping part at its tip for gripping the exhaust valve or the intake valve. The articulated robot performs a probing operation of horizontally moving the exhaust valve or the intake valve so that it naturally falls when it aligns with the valve guide hole on the upper surface of the cylinder head held by the rotary holding part with the gripping force released so that the exhaust valve or the intake valve does not fall. The gripping part includes a pushing part that presses the exhaust valve or the intake valve that has naturally fallen into the valve guide hole so as to incorporate it into the valve guide hole.

Advantages of the Invention

[0007] According to the above incorporation device, the valve can be assembled into the valve guide hole without having a special sensor or mechanism.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In the drawings, the same members are denoted by the same reference numerals, and redundant descriptions are omitted. In the drawings, the sizes and ratios of the respective members may be exaggerated for easy understanding of the embodiments and may be different from the actual sizes and ratios.

[0010] In each figure, the directions of the members constituting the vehicle structure according to the embodiment are indicated using arrows represented by X, Y, and Z. X indicates the depth direction and is denoted as the depth direction X. Y indicates the width direction of the device and is denoted as the width direction Y. Z indicates the height direction of the device and is denoted as the height direction Z.

[0011] FIG. 1 is a schematic perspective view showing an incorporation device 1 according to the embodiment. The valve according to this embodiment is attached to the cylinder head cy of the engine. The incorporation device 1 for incorporating the valve into the cylinder head cy includes an articulated robot 100, a valve supply device 200, and a tilt device 300 (corresponding to a rotation holding part). Details will be described below.

[0012] (Articulated Robot) Figures 2 to 11 are diagrams for explaining the articulated robot 100 that constitutes the embedding device 1, and Figures 12 to 15 are diagrams for explaining the probing operation by the articulated robot 100. Figure 16 is a diagram showing the exhaust valve V1, the valve guide hole h1 of the exhaust valve V1, the intake valve V2, and the valve guide hole h2 of the intake valve V2. In the following, the work of assembling the valve guide holes h1 and h2 of the exhaust valve V1 and the intake valve V2 will be described. The exhaust valve V1 and the intake valve V2 have substantially the same shape, and the valve guide holes h1 and h2 also have substantially the same shape. Therefore, in the following description, unless otherwise necessary, mainly the exhaust valve V1 and the valve guide hole h1 will be described, and the valve guide hole h1 will be shown in a simplified manner in the drawings other than Figure 16.

[0013] As shown in the figure, the articulated robot 100 connects a plurality of arms, and specifically, it is configured as a 6-axis robot. Each axis of the multi-axis robot is driven by an AC servo motor or the like. The articulated robot 100 can have six degrees of freedom. The articulated robot 100 can operate based on a coordinate system.

[0014] A gripping part 10 is provided at the tip of the articulated robot 100. The gripping part 10 includes arm parts 11 and 12 and a plurality of cylinders as shown in Figure 2 and the like. The articulated robot 100 performs a probing operation with the gripping force of the exhaust valve V1 released so that the exhaust valve V1 does not fall when the exhaust valve V1 is placed directly above the cylinder head cy while gripping the exhaust valve V1. The probing operation is performed by moving the exhaust valve V1 horizontally so that the exhaust valve V1 falls naturally when it aligns with the valve guide hole h1 (see Figure 15). Details will be described later.

[0015] The gripping portion 10 approaches the valve supply device 200 where the exhaust valve V1 is installed, and the arm portions 11 and 12 are in contact with the exhaust valve V1 so as to grip the exhaust valve V1 from both sides. As shown in FIGS. 9 and 10, the arm portions 11 and 12 are configured to be provided with claw portions 17 and 18 at different positions respectively. On one side of the arm portion 11, as shown in FIG. 9, a claw portion 17 is provided at approximately the center in the height direction Z, and the claw portion 17 has a flat tip surface.

[0016] The other arm portion 12 is provided with a claw portion 18 in a substantially V shape when viewed in plan at two positions in the height direction Z as shown in FIG. 10. At each position, the claw portion 18 is formed by arranging two convex shapes horizontally side by side. However, the number of convex shapes does not have to be two as long as the exhaust valve V1 can be gripped. The claw portions 17 and 18 of the gripping portion 10 described above are provided with DLC coating (Diamond Like Carbon coating), and the claw portions 17 and 18 are configured to be removable with respect to the arm portions 11 and 12. By configuring in this way, the wear resistance is improved so that the wear amount of the claw portions 17 and 18 does not increase during the probing operation described later when the exhaust valve V1 is clamped, and the life can be extended. Also, by making it possible to replace only the claw portions 17 and 18, the corresponding part can be replaced quickly.

[0017] Parallel air chucks 13 are provided at the base ends of the arm portions 11 and 12 as shown in FIGS. 2, 3, etc. Thus, if the pressure of the parallel air chucks 13 is increased, the arm portions 11 and 12 approach each other, and if the pressure is released, the arm portions 11 and 12 can be separated from each other. The gripping portions 10 are arranged so as to be arranged in three in the horizontal direction as shown in FIG. 2.

[0018] As shown in FIGS. 2, 4, etc., the plurality of cylinders include an interaxial pitch switching cylinder 14, a lip seal pushing cylinder 15 (corresponding to the pushing portion), and a valve insertion confirmation cylinder 16. The interaxial pitch switching cylinder 14 is configured to be able to adjust the pitch between the three arm portions 11 and 12 described above when gripping the exhaust valve V1 from the valve supply device 200 or when assembling the exhaust valve V1 to the cylinder head cy. In the present embodiment, the interaxial pitch switching cylinder 14 is configured to be able to adjust the pitch between the three arm portions 11 and 12 by moving the arm portions 11 and 12 at both ends of the three horizontally arranged arm portions 11 and 12 in the horizontal direction with respect to the central arm portions 11 and 12.

[0019] Regarding the pitch between the arm portions 11 and 12, it is preferable to make the pitch tolerance of the valve guide hole h of the cylinder head cy equal to the pitch tolerance between the arm portions 11 and 12 of the gripping portion 10. Also, the inclination (over the entire circumference) of the valve tip when the exhaust valve V1 is clamped is preferably set to a value smaller than the diameter of the probing operation described later. For example, if the diameter of the probing operation is 1 mm, by setting the inclination of the valve tip when clamped to be smaller than 1 mm, the inclination of the valve tip can be covered (absorbed) by the probing operation, and the valve can be inserted.

[0020] The lip seal pushing cylinder 15 is configured to push the exhaust valve V1 that has naturally fallen into the valve guide hole h1 into the valve guide hole h1. A lip seal is pre-assembled in the valve guide hole h1, and the assembly including the lip seal is completed by inserting the exhaust valve V1 through the valve guide hole h1.

[0021] The three insertion confirmation cylinders 16 perform a probing operation, cause the exhaust valve V1 to fall naturally, and check whether the exhaust valve V1 is inserted into the valve guide hole h1. The insertion confirmation cylinders 16 contact the head of the exhaust valve V1 to check whether the exhaust valve V1 is in the pre-fall position shown on the left in FIG. 11 or the post-fall position shown on the right. Then, by determining whether the contacted position is at a higher or lower position with a height difference d that is different before and after the natural fall, it is possible to check whether the exhaust valve V1 is inserted into the valve guide hole h1. The lip seal pushing cylinder 15 and the insertion confirmation cylinder 16 are configured to be able to move forward and backward in the extending direction of the cylinder and are provided with pushing pads at their tips.

[0022] (Valve supply device) FIGS. 17 to 19 are diagrams for explaining the valve supply device 200. The valve supply device 200 is a device that conveys the exhaust valve V1 to a predetermined position where the above-described multi-axis robot can grip the exhaust valve V1 when installing the exhaust valve V1 in the valve guide hole h1. The valve supply device 200 includes a supply path 210, a tilt section 220, and a lift section 230.

[0023] The supply path 210 is configured to convey a tray T on which a plurality of exhaust valves V1 can be placed. The supply path 210 is provided so as to extend in a substantially horizontal direction, and in this embodiment, it has an inclination angle of descending by about 3 degrees with respect to the horizontal direction from upstream to downstream. A plurality of rotating rollers can be provided on the supply path 210 to move the tray T from upstream to downstream at each position in the substantially horizontal direction.

[0024] The tilt section 220 is provided adjacent to the supply path 210 and is formed to have a shorter length in the conveyance direction than the supply path 210. The tilt section 220 is configured to be rotatable by a motor or the like with one end portion in the conveyance direction as a rotation axis. Thereby, the surface of the tray T conveyed to the tilt section 220 can be made substantially flush with the horizontal plane.

[0025] The lift unit 230 is configured to lift the exhaust valve V1 disposed on the tray T conveyed to the tilt unit 220 from below upward. The tray T on which the exhaust valve V1 is disposed is provided with a predetermined number of holes through which the stem portion of the exhaust valve V1 is inserted, and the lift unit 230 is configured to dispose a plate-like member that can move vertically below the tilt unit 220. When this plate-like member moves upward, as shown in FIGS. 18 and 19, the stem of the exhaust valve V1 protruding downward from the hole portion of the tray T comes into contact with the plate-like member, and the exhaust valve V1 moves upward by, for example, about 65 mm as much as the plate-like member rises.

[0026] Thereby, the gripping portion 10 of the articulated robot 100 can be made into a state where it is easy to grip the stem portion of the exhaust valve V1. Further, in the present embodiment, the exhaust valve V1 and the intake valve V2 are configured to be assembled to the cylinder head cy, and the valve supply device 200 can be configured with the same specifications for the exhaust valve V1 and the intake valve V2. The valve supply devices 200 for the exhaust valve V1 and the intake valve V2 can be installed at different positions within the range where the articulated robot 100 can grip the valves as shown in FIG. 1. Thus, in the present embodiment, the same valve supply device 200 is used for the exhaust valve V1 and the intake valve V2, and the exhaust valve V1 and the intake valve V2 are configured to be separately assembled by the articulated robot 100 into the valve guide holes h1 and h2.

[0027] (Tilt device) FIGS. 20 to 23 are diagrams for explaining the tilt device 300. The tilt device 300 rotatably holds the cylinder head cy on which the valve guide hole h1 is installed when the exhaust valve V1 is assembled into the valve guide hole h1 by the articulated robot 100. The tilt device 300 includes a lift unit 310 and a holding unit 320 as shown in FIG. 20 and the like.

[0028] The lift unit 310 is provided with a structure having a shape like a rail extending in the height direction Z to move the holding unit 320 up and down. The holding unit 320 is configured in pairs so as to grip both ends of the cylinder head cy from the outside in the width direction of the cylinder head cy, and each is configured to be movable inward and outward in the width direction. The paired holding units 320 are each provided with an insertion shape that can be inserted into a recess provided on the outside of the cylinder head cy on the inside thereof. Further, the holding unit 320 is provided with a shaft portion that can be rotated by a motor or the like.

[0029] Thus, by inserting a shape such as a pin into a recess or the like provided at both end portions of the cylinder head cy, the object such as the cylinder head cy can be moved up and down while being held, or the object such as the cylinder head cy can be rotated with the pin shape as the rotation center. The holding unit 320 can be provided with a stopper (not shown) for stopping the cylinder head cy at a predetermined angular position described later when the cylinder head cy reaches the predetermined angular position, and a proximity switch (not shown) for confirming that the cylinder head is at the angular position. Thereby, the cylinder head cy can be rotated to the angular position for assembling the exhaust valve V1 and the angular position for assembling the intake valve V2 by the tilt device 300, and the equipment cost can be reduced.

[0030] Further, a locating device 400 for placing the cylinder head cy conveyed from upstream before the holding unit 320 grips the cylinder head cy can be provided at the lower part of the tilt device 300 (see FIG. 21). The locating device 400 can move up and down in a state where the cylinder head cy or the like is placed thereon.

[0031] (Assembly method) Next, a method for assembling the exhaust valve V1 and the intake valve V2 according to the present embodiment will be described. FIG. 24 is a flowchart showing a method for assembling the exhaust valve V1 into the valve guide hole h1 by the assembling device 1. FIG. 25 is a subroutine flowchart of step S8 in FIG. 24.

[0032] First, by a conveying device (not shown), the cylinder head cy placed on the parent pallet above the locating device 400 is conveyed and stopped at a predetermined position by a stopper and an anti-back provided on the conveyor (see FIG. 20, S1). Next, in order to separate the pallet loaded with the cylinder head cy from contact with the conveyor roller, the locating device 400 lifts the entire pallet (see S2).

[0033] Next, the holding part 320 is lowered by the lift part 310 and stops at a predetermined height (see FIG. 22). Then, it moves from the outside to the inside in the width direction to clamp the cylinder head cy and the child pallet, and the lift part 310 moves upward (see FIG. 23, S3).

[0034] When the cylinder head cy is moved to a predetermined height, the holding part 320 rotates the cylinder head cy by about 180° so that the back side of the valve guide faces upward (S4). As a result, the insertion axis of the exhaust valve V1 in the valve guide hole h1 becomes an angle along the vertical direction (see FIG. 8).

[0035] In the valve supply device 200, with a predetermined number of exhaust valves V1 installed on the tray T, the tray T is conveyed by the rollers of the supply path 210 from the upstream to the downstream tilt part 220. When the tray T is conveyed to the tilt part 220, the tilt part 220 rotates the tray T at a predetermined angle along the horizontal direction, and the lift part 230 raises the exhaust valve V1 held by the tray T upward.

[0036] In the articulated robot 100, a program for operating the robot is loaded (S5). The articulated robot 100 grips the stem parts of three exhaust valves from the outside in the width direction by the arm parts 11 and 12 of the gripping part 10 and retracts from the spot (S6). Since the inter-axis pitch switching cylinder 14 is mounted on the gripping part 10 as described above, the pitch of the gripping part 10 can be adjusted to the pitch of the valve guide hole h.

[0037] Next, the proximity switch of the holding part 320 checks whether the insertion angle position of the exhaust valve V1 in the cylinder head cy is OK (S7). When the angle is not within the OK range (S7: NO), the holding part 320 rotates the cylinder head cy by a predetermined angle (S4) and checks whether the rotated angle is within the OK range (S7). When the angle is within the OK range (S7: YES), the articulated robot 100 starts the assembling operation of the exhaust valve V1 (S8).

[0038] Next, the articulated robot 100 approaches directly above the valve guide hole h1 while gripping the exhaust valve V1 (S9). Then, the articulated robot 100 releases the clamping pressure by the parallel air chuck 13 of the gripping part 10 (S10), brings the stem tip of the exhaust valve V1 close to the valve guide hole h1, and performs a probing operation (S11). At this time, the arm parts 11 and 12 maintain a state of lightly supporting the exhaust valve V1 and only release the pressure. In the probing operation, the multi-axis robot is moved in all directions so as to draw four circles with a diameter of 1 mm, for example, from the directly above position, and the stem tip of the valve moves as if it is searching for the valve guide hole (see FIGS. 12 to 15).

[0039] The moving direction is moved as 1→2→3→4→5→6→7→8→9→10→11→12→13→14→15→16→17 as indicated by the reference numerals shown by the dashed line on the upper surface of the valve guide hole h1 shown in FIG. 15. The movement of horizontally moving the exhaust valve V1 in various directions horizontally at a position where the exhaust valve V1 is likely to fall naturally directly above the valve guide hole h1 like this is the above-described probing operation. The probing operation is performed almost simultaneously on the three exhaust valves V1 gripped by the gripping part 10.

[0040] Since the tip of the exhaust valve V1 is inserted by natural fall, the upper end face sinks below the initial position (the position before falling). During the probing operation, the exhaust valve V1 falls naturally, but the timing is not intentional and varies depending on the variation of the valve tip in the clamped state. During the probing operation, the multi-joint robot 100 moves as shown in Fig. 15 in a circular motion so as to cover the tip variation, so the exhaust valve V1 surely falls.

[0041] As a result, the incorporation of the exhaust valve V1 into the valve guide hole h1 can be carried out without the need for special devices such as a suction mechanism or expensive sensors and mechanisms such as a force sensor. This can prevent or suppress the complication of the equipment for valve insertion and the increase in equipment costs. As will be described later, as long as the assembly is not NG, the exhaust valves V1 are inserted almost simultaneously, three at a time.

[0042] When the exhaust valve V1 has fallen into the valve guide hole h1, the insertion confirmation cylinder 16 is operated as shown in Fig. 5 to confirm that the exhaust valve V1 has been inserted into the desired position (S12). If the exhaust valve V1 has not been inserted into the desired position (S13: NO), it is confirmed again that it cannot be inserted (S14). And when it cannot be inserted (S14: NO), only the exhaust valve V1 that cannot be inserted is gripped (clamped) from the valve supply device 200 by the gripping part 10 (S15). When the case where it cannot be inserted continues (S14: YES), the valve insertion is terminated as an insertion abnormality (S16).

[0043] Then, the multi-joint robot 100 releases the clamping pressure of the exhaust valve V1 directly above the valve guide hole h1 again (S10), performs a probing operation (S11) and an insertion confirmation (S12). By clamping again, the inclination of the stem tip can be corrected, and thereby the exhaust valve V1 can be inserted into the valve guide hole h1. The exhaust valve V1 is inserted almost simultaneously by three valves as long as the exhaust valve V1 held by the arm parts 11 and 12 does not fail in this embodiment. By providing a plurality of locations where the gripping part 10 of the multi-joint robot 100 assembles the exhaust valve V1 in this way, the assembly time can be shortened compared to the case of assembling the valves one by one.

[0044] When the insertion confirmation of the exhaust valve V1 is successful (S13: YES), the arm parts 11 and 12 are retracted from the exhaust valve V1 (S17). And since it is necessary to pass the exhaust valve V1 through the lip seal part for the incorporation of the exhaust valve V1, the exhaust valve V1 is pushed in from the upper surface almost simultaneously by three valves by the lip seal pushing cylinder 15 (S18). Thus, the first assembly of the exhaust valve V1 is completed.

[0045] In this embodiment, since six exhaust valves V1 are attached to the cylinder head cy, the multi-joint robot 100 operates to grip three more exhaust valves V1 from the valve supply device 200 (S19). Then, the operations from step S9 to S18 described above are repeated. Thereby, the remaining three exhaust valves V1 can be assembled to the cylinder head cy (S20).

[0046] Since the intake valve V2 is assembled to the cylinder head cy at an angle different from that of the exhaust valve V1, next, the holding part 320 adjusts the position of the cylinder head cy in the angular direction to the angle at which the intake valve V2 is assembled (S21). At the same time, the multi-joint robot 100 grips three intake valves V2 from the valve supply device 200 in the same manner as in step S6 (S22).

[0047] If it cannot be confirmed by the proximity switch of the holding part 320 that the cylinder head cy is at an angular position where the intake valve V2 can be assembled (S23: NO), the holding part 320 is rotated to adjust the angular position of the cylinder head (S21). When the angular position of the cylinder head cy reaches the OK position (S23: YES), the articulated robot 100 performs the assembly operation of the intake valve V2 in the same manner as in steps S9 to S18 (S24). In this embodiment, six intake valves V2 are installed in the cylinder head cy in the same manner as the exhaust valve V1. Therefore, the articulated robot 100 further grips three intake valves V2 from the valve supply device 200 (S25), and performs the operations from step S9 to S18 to assemble the intake valves V2 into the valve guide holes h2 of the cylinder head cy (S26).

[0048] When the exhaust valve V1 and the intake valve V2 are assembled to the cylinder head cy, the holding part 320 rotates the angular position of the cylinder head cy to the position at the initial stage of loading (S27). Then, the lift part 310 is lowered (S28), the locate device 400 is lowered (S29), and the work pallet is carried out (S30).

[0049] Note that the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. In the above, the gripping part 10 is provided with three locations for gripping the exhaust valve V1, but the number of gripping locations does not have to be three.

Explanation of Reference Numerals

[0050] 10 Gripping part 11 Arm part 12 Arm part 15 Cylinder for pressing in lip seal (pressing part) 17, 18 Claw parts 300 Tilt device (rotation holding part) cy Cylinder head h1, h2 Valve guide holes V1 Exhaust valve V2 Intake valve X Depth direction Y width direction, Z height direction.

Claims

1. An incorporation device for incorporating an exhaust valve or an intake valve into a cylinder head, a rotary holding part for rotatably holding the cylinder head, and a multi-joint robot having a gripping part for gripping the exhaust valve or the intake valve at its tip, the multi-joint robot performs a probing operation of horizontally moving the exhaust valve or the intake valve so as to freely fall at a point when the exhaust valve or the intake valve is aligned with the valve guide hole on the upper surface of the cylinder head held by the rotary holding part in a state where the gripping force is released so that the exhaust valve or the intake valve does not fall, the gripping part is an incorporation device provided with a pushing-in part for pressing the exhaust valve or the intake valve that has freely fallen into the valve guide hole so as to incorporate it into the valve guide hole.

2. The incorporation device according to claim 1, wherein the gripping part has a plurality of portions for gripping the exhaust valve or the intake valve.

3. The incorporation device according to claim 1, wherein the rotary holding part can rotate the cylinder head to an angular position for assembling the exhaust valve and an angular position for assembling the intake valve.

4. The gripping part is provided with a DLC coating, the gripping part includes a claw part that can contact the exhaust valve or the intake valve, and an arm part for removably attaching the claw part, and is the incorporation device according to any one of claims 1 to 3.

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