JPH07237047A - Workpiece holding device - Google Patents

Abstract

PURPOSE:To provide a workpiece holding device which can hold a bar like workpiece such as an engine valve in the specified attitude of being extended along the vertical direction. CONSTITUTION:A weight member 24 is oscillatingly supported by supporting the part, excluding the center-of-gravity, on a holder block 22 provided with workpiece holding holes 22A, 22B for holding a valve V, a workpiece, in the state of being vertically extended, and the valve V piercingly inserted into the workpiece holding holes 22A, 22B of the holder block 22 is brought into pressure contact with the inner peripheral surface of the workpiece holding holes 22A, 22B by the weight member 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work holding device, and more particularly to a work holding device for holding a rod-like work such as an engine valve.

[0002]

2. Description of the Related Art For example, in a production line of a four-cycle engine mounted on a motorcycle or the like, a valve inserting device for inserting a valve stem of a valve into a valve guide of the cylinder head and assembling the valve to the cylinder head, The applicant of the present application has proposed in Japanese Patent Application No. 5-229017. This valve insertion device includes a holder block that holds the valve in a predetermined posture with the valve head positioned above, and a biasing unit that biases the valve held by the holder block upward. A holding unit, and further has a reference seat abutting against the valve head end surface of the valve, and a hand means for gripping the valve stem of the valve abutting the reference seat, and between the valve holding unit and the cylinder head. Is equipped with a valve insertion unit movably provided. Then, the valve head is positioned above the holder block of the valve holding unit to hold the valve, and then the reference seat of the valve insertion unit is brought into contact with the valve head to resist the biasing means of the valve holding unit. After being pressed against the valve head, the valve stem of the valve is gripped by the hand means of the valve insertion unit. As shown in FIG. 21, the valve holding unit A includes a holder block B having a U-shaped cross section, and an upper protrusion portion Bu and a lower protrusion portion Bl of the holder block B have valve stems of the valve V, respectively. Work holding hole Cu through which Va is inserted
And Cl are formed. Further, the lower protrusion Bl
Is equipped with a spring plunger unit D, with the valve head Vb of the valve V facing upward,
By inserting the valve stem Va into the work holding holes Bu and Bl, the valve V is held in a posture extending vertically as shown in the drawing.

[0003]

By the way, in the valve holding unit A, in order to smoothly insert the valve stem Va of the valve V into the respective work holding holes Cu and Cl of the holder block B, the respective work holding holes Cu. The inner diameter of Cl and Cl are set to be slightly larger than the outer diameter of the valve stem Va. For this reason, the valve V held by the holder block B is loosened with respect to the holder block B, and is often held in an inclined state, so that the posture is not constant. However, there is a problem in that the valve V is taken out from the container and is conveyed, resulting in a defective operation in the next step. In view of the above situation, an object of the present invention is to provide a work holding device capable of holding a rod-shaped work such as an engine valve in a predetermined posture extending in the vertical direction.

[0004]

In a work holding apparatus according to the present invention, a weight member is supported on a portion other than the center of gravity of a holder block provided with a work holding hole for vertically extending and holding a work. Thus, the work inserted into the work holding hole of the holder block is pressed against the inner peripheral surface of the holding hole by the weight member.

[0005]

In the above construction, the weight member presses the work against the inner peripheral surface of the work holding hole in the holder block, so that the work does not rattle with respect to the holder block and is fixed to the holder block. It will be supported in position.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing one embodiment. 1 to 15 show an example in which the present invention is applied to an automatic assembling machine used in a process of assembling a valve to a cylinder head in a production line of a 4-cycle engine.

The automatic assembly machine 1 has a carry-in conveyor 3 for carrying in the parts container 2 from the outside, and a discharge conveyor 4 for carrying out the parts container 2 to the outside. Is provided with an elevator conveyor 5 (see FIGS. 4 and 5) that moves up and down between the above conveyors.

The automatic assembly machine 1 also includes a parts loader 10 for taking out and transferring a valve V (see FIG. 5) from a parts container 2, and a valve V from the parts loader 10.
The valve holding unit 20 for receiving and holding the valve holding unit 20 and the valve inserting unit 30 for taking out the valve V from the valve holding unit 20 and assembling it to the cylinder head H (see FIG. 1).
0 and the valve insertion unit 30 constitute a valve insertion device 100.

The parts loader 10 is shown in FIGS.
The guide frame 11 extends horizontally across the parts container 2 as shown in FIG.
Further, as shown in FIG. 6, the parts loader 10 has eight vacuum pads 12 for sucking and holding the valve V.
And the vacuum pads 12 are accommodated in a line in the vertical direction of the parts container 2 8
Two valves are arranged in parallel for each of the four cylinders 13 at the same pitch as the interval between the valves V, V.

Further, as shown in FIGS. 1 to 3, the valve holding unit 20 and the valve inserting unit 3 are provided.
0 is movably provided with respect to a guide frame 21 and a guide frame 31 that extend horizontally along the loading direction of the parts container 2 (the left-right direction in FIGS. 1 and 2), and in FIG. Holding unit 2
When 0 goes to the right and the valve insertion unit 30 goes to the left, the valve V is transferred between the two.

As shown in FIGS. 7 to 10, the valve holding unit (valve holding device) 20 is provided with a holder block 22 extending along the guide frame 21 (see FIGS. 4 and 5). The holder block 22 has a U-shaped cross section, and includes an upper protrusion 22U and a lower protrusion 22L, and a wall 22W connecting the protrusions 22U and 22L to each other.

Workpiece holding holes 22 into which the valve stem Va of the valve V is inserted are formed in the upper protruding portion 22U and the lower protruding portion 22L of the holder block 22, respectively.
A and 22B are formed, and the lower protruding portion 2 is further formed.
A spring plunger unit 23 is installed in 2L in a manner that the plunger 23a faces the work holding hole 22B.

A valve V as a work having a rod shape is
By inserting the valve stem Va into the work holding hole 22A and the holding hole 22Bb with the valve head Vb facing upward, the valve V is moved to the valve stem Va.
The holder block 22 in a posture in which the
Will be housed and held in.

As shown in FIGS. 7 and 8, the work holding holes 22A and 22B and the spring plunger unit 23 in the holder block 22 are provided at eight positions and eight, respectively, and are held by the parts loader 10. It is configured to receive 8 valves V as well.

Further, as shown in FIG. 8, the wall portion 22W of the holder block 22 has the above-mentioned work holding holes 22.
A total of eight weight members 24 are provided in a manner corresponding to A and 22B.

As shown in FIGS. 9 and 10, the weight member 24 has a short cylindrical shape, and a support hole 24a is formed at a position deviated from the center of gravity, and the wall of the holder block 22 is formed. In the shoulder bolt 25 as a spindle provided in the portion 22W, the support hole 24
By loosely fitting a, it is swingably supported with respect to the holder block 22.

The shoulder bolt 25 is attached to the wall 2
Perpendicular to 2W, in other words each work holding hole 22A
And 22B are provided so as to project in a direction orthogonal to the juxtaposed direction of the workpiece holding holes 22A and 22B.
The weight member 24 in a normal state is provided so as to project from a center axis OO of B by a distance slightly smaller than the radial dimension of the weight member 24.
Is the valve V when held by the holder block 22.
Will be located in the space occupied by the occupants in a manner in which some of them interfere with each other.

The inner diameter of the support hole 24a in the weight member 24 is set to be sufficiently larger than the outer diameter of the shoulder bolt 25, so that even if some dust or dust is caught, The weight member 24 can be lightly swung with the shoulder bolt 25 as a fulcrum.

According to the above configuration, the automatic assembling machine 1 described later
During operation, the valve stem Va of the valve V moves from above the holder block 22 to the work holding holes 22A and 2A.
2B, the weight member 24 is pushed rightward in the figure by the valve stem Va, and is swung from the normal position shown by the chain line in FIG. 9 to the biasing position shown by the solid line in the figure. It

As a result, the work holding holes 22A and 22
The valve V inserted in B is pressed toward the left side in the drawing by the weight member 24 that tries to return from the biasing position to the normal position, and as shown in FIG. 9, the work holding holes 22A and 22B are not pressed. By being pressed against the inner peripheral surface, the valve V is held without rattling with respect to the holder block 22 and is supported at a fixed position with respect to the holder block 22.

Here, while the valve V as a work is generally made of heat-resistant SUH-based special steel, the weight member 24 in the work holding device 20 is more than the valve V. It is made of SB-2 (brass) having a low hardness, that is, a material softer than the valve V. Therefore, for example, when the valve V is accommodated in the holder block 22, even if the valve V and the weight member 24 are in sliding contact with each other, the valve V as a work is not inadvertently damaged. The material forming the weight member 24 may be a soft material having a relatively high density, and a copper-based metal material or the like is preferable to satisfy the above conditions.

On the other hand, as shown in FIGS. 11 to 14,
The valve insertion unit 30 includes a cylinder 33 mounted on a base frame 32 that horizontally moves along a guide frame 31.
An elevating frame 34 provided via the, and a reference seat block 40 and a hand means 50 provided on the elevating frame 34. Note that the code 3 in FIG.
Reference numeral 3a is an operating rod of the cylinder 33, reference numeral 35 is a guide rod provided on the elevating frame 34, and reference numeral 36 is a guide sleeve provided on the base frame 32.

The reference seat 40 is composed of a block having a substantially cylindrical shape, is fixed to the lower surface of the elevating frame 34, and has its lower end at the end surface of the valve head Vb of the valve V (see FIG. 12). A pressing surface 40a that comes into contact with the upper surface) is formed, and a through hole 40b formed in the central portion of the reference seat block 40 further has an operating rod 41a of the valve insertion cylinder 41 attached to the elevating frame 34. Is loosely fitted.

On the other hand, the hand means 50 is a hand unit 5 comprising a pair of hands 51a and a cylinder 51b.
1 and a cylinder 52 for moving the hand unit 51 forward and backward to the positions shown by the solid line and the chain line in FIG. 12, and as shown in FIGS. 12 and 13, the hand unit 51 moves up and down. A slide plate 54 movably provided in the front and rear (left and right in FIG. 12) with respect to the frame 34 by rails 53a and sliders 53b.
And a horizontal 2 which is orthogonal to the elevating plate 34 via an intermediate plate 56 which is provided to the slide plate 54 by a rail 55a and a slider 55b so as to be movable left and right (left and right in FIG. 13). It is movably supported along the axial direction.

As shown in FIGS. 12 and 14,
The slide plate 54 includes the slide plate 5
Thin leaf spring 57 as a supporting member fixed to the end of 4
While the operating rod 52a of the cylinder 52 is connected through the slide plate 54 and the intermediate plate 56, the slide plate 54 and the intermediate plate 56 are mutually connected via a thin leaf spring 58 as a supporting member, as shown in FIGS. When the leaf spring 57 and the leaf spring 58 are connected to each other and allow the hand unit 51 to move forward, backward, leftward and rightward by being deformed, an external force is not applied to the hand unit 51 from the horizontal direction. First, the hand unit 51 is held at the position facing the reference seat 40 on the basis of each elastic return force. A stopper plate 54A that is loosely fitted in the opening 56a of the intermediate plate 56 is attached to the slide plate 54. This allows the intermediate plate 56 to move with respect to the slide plate 54, and The intermediate plate 56 is prevented from falling off.

When the automatic assembly machine 1 is in operation, the parts container 2 sent to the elevating conveyor 5 via the carry-in conveyor 3 is guided by the side guide 6a shown in FIG. It is set to the working position. After all the valves V, V ... Are taken out, the parts container 2 is sent out of the automatic assembly machine 1 from the descending elevator conveyor 5 via the discharge conveyor 4.

When the parts container 2 is set to the working position, the eight valves V, V in one row in the parts container 2 are simultaneously taken out by the parts loader 10 and transferred to the valve holding unit 20 and then the valves. Each of the holder blocks 22 of the holding unit 20 is housed with the valve head Vb facing upward.

Here, as shown in FIGS. 4 and 5, a tank 7 for storing a lubricant such as oil is arranged in the vicinity of the valve holding unit 20, and arrows a to g in FIG. As shown in, the valve V taken out of the parts container 2 by the parts loader 10 is housed and held in the holder block 22 of the valve holding unit 20 after the valve stem is immersed in the lubricant in the tank 7.

When the valve V is held by the holder block 22, the valve holding unit 20 and the valve insertion unit 30 move relative to each other, and the valve held by the valve holding unit 20 is moved as shown in FIG. 15 (a). The reference seat 40 of the valve insertion unit 30 is located in the region directly above V. At this time, the hand unit 51 of the valve insertion unit 30 is occupied at the retracted position by the retracting operation of the cylinder 52.

After this, the operating rod 33a of the cylinder 33 in the valve insertion unit 30 expands and the reference seat 40 descends, whereby the pressing surface 4 of the reference seat 40 is lowered.
0a comes into contact with the end surface (upper surface) of the valve head Vb, and the reference seat 40 is further lowered, so that the valve V is moved to the position shown in FIG.
5 (b) is pressed from the position indicated by the chain line to the position indicated by the solid line.

When the valve V is pushed down by the reference seat 40, the plunger 32a of the spring plunger unit 32 in the valve holding unit 20 moves to the valve V
The valve head Vb of the valve V and the pressing surface 40a of the reference seat 40,
They will be strongly pressed against each other.

After that, the hand unit 51 of the valve insertion unit 30 is advanced by the extension operation of the cylinder 52, and the pair of hands 51a of the hand unit 51 grip the valve stem Va of the valve V, whereby the valve The V is held in a predetermined posture with respect to the valve insertion unit 30.

After the valve V is gripped by the hand unit 51, the operating rod 33a of the cylinder 33 in the valve insertion unit 30 retracts, the valve V is pulled out from the holder block 22, and then the valve V is inserted. Based on the movement of the unit 30, the cylinder head H set to the working position as shown in FIG.
Is transferred to the upper area of.

The valve V transferred to the upper region of the cylinder head H is the cylinder 3 in the valve insertion unit 30.
When the operation rod 33a of No. 3 is retracted, the operation rod 33a is lowered to a position directly above a valve guide (not shown) provided in the cylinder head H, and then the valve insertion cylinder 41
The valve stem Va of the valve V is inserted into the valve guide by the extension operation of the operating rod 41a.

A pair of hands 51a in the hand unit 51 holding the valve V when the valve V is inserted.
After releasing the valve stem Va into the valve guide, the valve stem Va is released at an appropriate timing, while the hand unit 51 prevents the pair of hands 51a from buffering the valve head Vb. Before Vb passes, the cylinder 52 is retracted by the retracting operation. After that, the parts loader 10, the valve holding unit 20, the valve insertion unit 30, and the like repeat operations in accordance with the steps described above, whereby the work of assembling the valve with the cylinder head is performed.

In the work holding device 20 'shown in FIGS. 16 to 18, a window 22H' is opened in a wall portion 22W 'of a holder block 22' and a spindle extending horizontally in the wall portion 22W '. 25 'is the clamp piece 26'
Is fixed to the support shaft 25 'through the window 2
A weight member 24 'is swingably supported so as to pass through the wall portion 22' facing 2H '.

The weight member 24 'is in the form of a short cylinder having a short length, as is clear from the figures, and a portion deviated from the center of gravity is supported by the support shaft 25' and is in a normal state. The weight member 24 'is located in a space where a part of the weight member 24' interferes with the space occupied by the valve V held by the holder block 22 '.

Here, the weight member 24 'is made of SB-2 (brass) which is softer than the valve V, and enters the space occupied by the valve V when held by the holder block 22'. A through hole 24A 'is formed at an eccentric position in order to shift the center of gravity so that a part of the hole sufficiently interferes in the normal state.

The work holding device 20 'is basically the same as the work holding device 20 shown in FIGS. 1 to 15 except for the structure related to the weight member 24' described above. Holding device 2
A component that has the same effect as the component at 0 is
Detailed description will be omitted by adding ′ (dash) to the same reference numerals as those in FIGS. 1 to 15.

According to the work holding device 20 'having the above-described structure, the valve stem Va of the valve V has the work holding hole 22.
When inserted into A'and 22B ', the weight member 24' is swung from the normal position shown by the chain line in FIG. 17 to the biasing position shown by the solid line, whereby the valve V is
Weight member 2 that tries to return from the biased position to the normal position
4'by the work holding hole 22A 'as shown in FIG.
And 22B 'are pressed against the inner peripheral surface of the holder block 2
It is supported at a fixed position without rattling with respect to 2 '.

The weight member 24 'is connected to the valve V.
Since it is made of a material such as SB-2 (brass) which is softer than the above, even if the valve V and the weight member 24 'are in sliding contact with each other, the valve V as a work may be inadvertently damaged. Absent.

Further, the work holding device 20 'having the above structure.
Since the weight member 24 'is oscillated and supported by penetrating the wall portion 22W' of the holder block 22 ', each work piece of the holder block 22' is held without considering interference between the weight members 24 '. Holes 22A 'and 22
It is possible to set the interval B'to be as narrow as possible, so that it is possible to achieve the miniaturization of the external appearance of the work holding device 20 '.

In the work holding device 20 "shown in FIGS. 19 and 20, the weight member 24 'in the work holding device 20' described above is replaced by an S softer than the valve V.
It is made of B-2 (brass) or the like, and has a side for the purpose of shifting the center of gravity into the space occupied by the valve V when it is held by the holder block 22 ″ so that a part of it interferes sufficiently in the normal state. A weight member 24 "having a notch 24B" formed in the portion is used.

In the work holding device 20 ", except for the construction related to the weight member 24" described above, the work holding device 20 'shown in FIGS.
The work holding device 20 'is the same as the work holding device 20'.
Elements having the same functions as those described above are denoted by the same reference numerals as those in FIGS. 16 to 18 with “(double dash), and detailed description thereof will be omitted.

According to the work holding device 20 "having the above-described structure, the valve V as a work is rattled with respect to the holder block 22" based on the operation of the weight member 24 ", like the work holding device 20 'described above. It is possible to support the valve V at a fixed position without any damage, and at the same time, it is possible to hold the valve V on the holder block 22 ″ without carelessly damaging it, and it is also possible to achieve miniaturization of the external appearance.

The above-mentioned work holding devices (20,
20 ', 20 ") weight members (24, 2)
4 ', 24 ") is basically a cylindrical shape for the purpose of simplifying the production, but various shapes can be used as long as it is a smooth shape such as an ellipse, an egg, a jewel, or a bell. It is also possible to adopt.

[0047]

As described above in detail, in the work holding apparatus according to the present invention, the holder block having the work holding holes for vertically extending and holding the work,
The weight member supports a portion other than the center of gravity so as to be swingable, and the work inserted through the work holding hole of the holder block is pressed against the inner peripheral surface of the holding hole by the weight member. is doing. According to the above-described configuration, the weight member presses the work against the inner peripheral surface of the work holding hole in the holder block, so that the work does not rattle with respect to the holder block and has a constant position with respect to the holder block. Therefore, according to the work holding device of the present invention, it is possible to hold a rod-shaped work such as an engine valve in a predetermined posture extending in the vertical direction.

[Brief description of drawings]

FIG. 1 is an overall front view of an automatic assembly machine including a work holding device according to the present invention.

FIG. 2 is an overall plan view of an automatic assembly machine.

FIG. 3 is an overall side view of the automatic assembly machine.

FIG. 4 is a plan view of relevant parts showing the periphery of a parts loader in an automatic assembly machine.

FIG. 5 is a side view of essential parts showing the periphery of a parts loader in the automatic assembly machine.

FIG. 6 is a side view of essential parts showing a parts loader of the automatic assembly machine.

FIG. 7 is an overall perspective view showing a work holding device according to the present invention.

8A and 8B are a plan view and a front view showing a work holding device according to the present invention.

FIG. 9 is a sectional front view of a main part of the work holding device according to the present invention.

10 is a sectional view taken along line I-I of FIG.

FIG. 11 is an overall front view showing a valve insertion unit.

FIG. 12 is a cross-sectional side view of essential parts showing a valve insertion unit.

FIG. 13 is a front view of an essential part showing a part around the hand means of the valve insertion unit in a partially broken manner.

FIG. 14 is a bottom view of the essential parts showing the periphery of the hand means in the valve insertion unit.

15 (a) and 15 (b) are operation conceptual diagrams of the valve insertion device.

FIG. 16 is a cross-sectional front view of essential parts showing another embodiment of the work holding device according to the present invention.

17 is a sectional view taken along the line II-II of FIG.

18 is a sectional view taken along line III-III in FIG.

FIG. 19 is a cross-sectional front view of a main part showing still another embodiment of the work holding device according to the present invention.

20 is a sectional view taken along line IV-IV of FIG.

FIG. 21 is a cross-sectional side view of essential parts showing a conventional work holding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Automatic assembly machine, 10 ... Parts loader, 20 ... Valve holding device, 22 ... Holder block, 22U ... Upper protrusion part, 22L ... Lower protrusion part, 22W ... Wall part, 22A, 22B ... Work holding hole, 24 ... Weight member, 25 ... Spindle, V ... Valve (work), Va ... Valve stem.

Claims (3)

[Claims] 1. A holder block having a work holding hole through which a rod-shaped work is inserted and holding the work in a posture extending in the vertical direction, and a portion other than the center of gravity is supported by the holder block to shake. Is movably supported, is pushed from the normal position by the work penetrating the work holding hole, and abuts the work penetrating the work holding hole to bring the work into the inner peripheral surface of the holding hole. A work holding device comprising: a weight member to be brought into pressure contact with. 2. The work holding device according to claim 1, wherein the weight member is made of a material having a hardness lower than that of a work held by the work holder. 3. The holder block has a U-shaped cross section including a wall portion, an upper protruding portion and a lower protruding portion, and the weight member extends along the wall portion of the holder block. The work holding device according to claim 1, wherein the work holding device is swingably supported on a support shaft extending horizontally in a manner penetrating the wall portion.