JPH0248187Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The disclosed technology is a structural technology field of an assembly device that fits a corresponding workpiece without a gap into a hole with a circular cross section of a metal block-shaped object to be installed. belongs to

Therefore, this invention has an integrated workpiece holding part such as a vacuum type at the tip for attaching a workpiece to a hole in a metal block such as a valve lifter installed in a cylinder head of an automobile engine. This invention relates to a workpiece assembly device in which a rod is linked to a lifting actuator such as an air cylinder to adsorb a workpiece waiting in a supply section, convey it to a workpiece, and fit it into a hole. A casing with a circular cross section is connected to the lifting actuator, and a rod housed in the casing is rotatable with respect to the casing and is pivotally installed via a radial bearing and a thrust bearing so as to be able to move up and down. This invention relates to a workpiece assembling device in which a rod provided through an elastic body is linked to a casing through a rotating cam such as a worm screw.

<Prior art> As is well known, there are many cases in which a piece-like part that fits into a circular hole drilled in a predetermined part of an object to be attached, such as a block of metal products, is assembled. There are various types of assembly, such as the assembly of cylinder heads and valve lifters in engines.

In this case, the workpiece is not simply fitted into the hole of the object to be mounted, but the hole and the workpiece are fitted extremely tightly due to gas sealing properties, etc., and the so-called fitting gap is extremely small. Automatic assembly is strongly desired to improve accuracy and work efficiency, but the swing movement of the assembly device that holds the workpiece from the workpiece chute to the hole in the object to be mounted while the workpiece is continuously supplied from the supply chute is highly desirable. Therefore, there is a basic difficulty in that it is difficult to achieve mutual positioning accuracy between the hole and the work by holding the end of the assembly every time there is a swing. Errors during manufacturing in positional accuracy and workpiece size accuracy also make it extremely difficult, and the presence of positional deviation is a prerequisite.

On the other hand, for example, "Mechanical Design Vol. 29 No. 5
As shown in the so-called variable compliance device technology shown in "No.", pages 53 to 57, complex position correction mechanisms using visual sensors, tactile sensors, etc. have been developed, but the basic In addition, means have been developed to automate the fitting work, which requires the highest positioning accuracy among assembly work.

<Problems to be solved by the invention> However, as mentioned above, although this type of position correction mechanism improves the functionality of controlled robots, the overall structure is extremely complicated, and the line in which it is applied is limited. The development of this technology requires complex design applications, which have the disadvantage of being difficult to manage and control, resulting in high costs.

Moreover, there is a risk that troubles may occur frequently due to unforeseen factors during on-site operations, and in reality, the line unavoidably relies on manual work, resulting in poor line workability. .

The purpose of this invention is to solve the technical problem of assembling a workpiece into a hole in an attached object with an extremely small fitting clearance based on the above-mentioned conventional technology, and to solve the problem of assembling a workpiece into a hole in a workpiece with an extremely small fitting clearance. If interference occurs, by rotating the two relative to each other, automatic centering will occur after a short period of time, and a smooth and stable fit can be achieved.This is based on conventional experimental results. It is an object of the present invention to provide an excellent workpiece assembling device which is useful in the field of centering technology in the machine manufacturing industry by correcting the pushing action and automatically assembling the workpiece.

<Means/effects for solving the problem> In order to solve the above-mentioned problem, the structure of this invention, which is based on the scope of the above-mentioned utility model registration claim, is to solve the above-mentioned problem. The workpiece is held by a holding device at the tip of the rod inserted inside and brought close to the hole of the object to be installed, and the workpiece is brought close to the hole by lowering of a lifting actuator such as an air cylinder connected to the casing, and alignment is performed by automatic centering. If the lifting actuator is lowered, the workpiece will be fitted into the hole, and if the workpiece interferes with the circumference of the hole due to relative misalignment between the two, the casing will continue to descend, and the rod inserted inside will fit into the hole. The rod is displaced relative to the casing by an elastic body such as a compression spring, and the casing, which continues to descend with respect to the rod, automatically applies a rotational action to the rod via a rotating cam such as a worm screw. The workpiece begins to rotate relative to the hole, and the workpiece is immediately automatically centered in the hole, so that the workpiece is precisely and automatically fitted into the hole.

<Example> Next, an example of this invention will be described below based on the drawings.

Reference numeral 1 denotes a workpiece assembly device which constitutes the gist of this invention, and as shown in FIG. It is provided on a bracket 7 provided at the lower end of an air cylinder 6, which serves as an elevating actuator, which is fixed to a mounting body 5, and is movable up and down.

Therefore, the assembly device 7 is operated by the industrial robot 3 and the lifting actuator 6 to assemble a chute 8 to a short cylindrical workpiece 9 fed by a parts feeder (not shown) provided on the base 2.
A predetermined assembly tool 11, 11 is attached to the positioning device 10 provided on the base 2 while holding the workpiece 9.
The workpieces 9 are alternately and accurately automatically assembled and fitted into the circular holes 15, 15' in the upper part of the object to be mounted 14 set through the workpieces 14.

As shown in FIGS. 1 and 2 in detail, in the assembly device 1 that forms the gist of this invention, the bracket 7 of the air cylinder 6 as an actuator is assembled into a ring-shaped cross section by bolts 16, 16... A cylindrical casing 17 is fixedly provided and is movable up and down by an air cylinder 6, and a rod 19 inside the casing 17 rotates relative to the casing 17 via a radial bearing 18, and is moved up and down. A boss 21, which is freely pivoted and protrudes downward from the lower part of the flange 20 at the lower end thereof, is connected to the upper end of the rod 19 through a hole 23 which is provided with a recess 22 and passes concentrically through the inside of the rod 19. A hose 25 connected to the provided nipple 24 is connected to a vacuum device (not shown), and the workpiece 9 is suctioned and held at the tip of the boss 21.

Therefore, the boss 21 forms a workpiece holding section.

Then, at the upper end of the rod 19, the nipple 24
A cover-type stopper 27 is provided by a nut 26 screwed into the lower part of the casing 17, and abuts against the upper surface 29 of a collar 28 fixed to the upper end of the casing 17 by a bolt 16'.

In addition, a female thread 3 carved on the inner surface of the collar 28
The male screw 31 of the rod 19 is screwed into the rod 19, but the screw pitch of both is large, about 45 degrees, and both form a rotating cam.

A compression spring 33 as a resilient body is interposed between the lower end flange 20 of the rod 19 and the casing 17 via a thrust bearing 32 so that the rod 19 always projects downward relative to the casing 17. is energized.

As shown in FIGS. 1 and 2, the casing 17 and the rod 19 are engaged by a rotating cam of a female thread 30 of a collar 28 fixed to a bolt 16' on the casing 17 and a female thread 31 of the rod 19. Therefore, protrusion is prevented.

In the above configuration, the work 9 is as described above.
Parts are continuously supplied from the parts feeder device to the chute 8 and are on standby, and the industrial robot 3 uses its arm 4 to insert the assembly device from the chute 8 into the holes 15 and 1 of the object to be attached 14 according to a predetermined program.
The workpieces 9 are sequentially conveyed and fitted into the holding part 5', and a vacuum device (not shown) applies negative pressure to the recess 22 of the protruding part 21 of the holding part through a hose 25 to adsorb the workpiece 9. The casing 17 is positioned as close as possible to the tops of the holes 15, 15 in an adsorbed state, and the casing 17 is lowered via the bracket 7 by the air cylinder 6. In this case, the work 9 and the holes 15, When the centering of the holes 15' is done, the workpiece 9 is automatically fitted into the holes 15, 15'.

Therefore, in such a case, even if the fitting gap is extremely small, the workpiece 9 can be accurately fitted into the holes 15, 15' without any problem and smoothly.

As mentioned above, due to manufacturing errors in the entire device and the positioning device 10, as well as minute vibrations during the operation of the industrial robot 3, the work 9 and the object to be mounted may be distorted as shown in FIG. If there is a difference in the misalignment ΔX between the two holes 15', the holes 15'
The edge 34 of the workpiece 9 interferes with the workpiece 9, and due to the contact between the two, the workpiece 9 cannot be fitted into the hole 15'.

Of course, the misalignment ΔX in this case is extremely small, but on the other hand, if precise fitting is to be performed, the minute misalignment of ΔX will hinder the fitting.

Therefore, in the process of said interference, the air cylinder 6
The bracket 7 continues to move downward, so that the casing 17 continues to fall from the outside of the thrust bearing 32 to cover the flange 20 of the rod 19, and the compression spring 33 tends to be compressed.

Therefore, the compression force of the compression spring 33 applies a pushing force to the holding part 21, that is, the workpiece 9, to the edge 34 of the hole 15', but in this process, the casing 17 is lowered relative to the rod 19. In order to do this, the female thread 30 of the collar 28, which is integrally provided at the upper part of the casing 17, acts as a rotating cam to rotate the male thread 31 of the rod 19. During the descending process, it begins to rotate as shown by the arrow in Figure 2.

Since both the pressing force and rotational force are applied to the workpiece 9 in the direction of the hole 15', the workpiece 9 has a small misalignment ΔX, so the fitting gap in which automatic centering is immediately performed becomes small. Nevertheless, both are automatically fitted, and the workpiece 9 is fitted into the hole 15' as set.

Then, the above-mentioned process occurs at the same time that the workpiece 9 comes into contact with the edge 34 of the hole 15', and automatic centering is immediately performed so that the workpiece 9 fits into the hole 15'.

Of course, when the tip of the workpiece 9 hits the edge 34 of the hole 15', rotation starts because the pitch between the male screw 31 and the female screw 30 of the upper rotating cam is as large as 45 degrees, and the tip of the workpiece 9 hits the edge 34 of the hole 15'. will not cause any damage.

After the fitting is completed, the negative pressure from the vacuum device is cut off and the air cylinder 6 is raised.
Following the reverse process to the above process, the assembly device 1 rises, but since the vacuum negative pressure is cut off from the workpiece 9 to the holding part 21, the workpiece 9 is fitted into the hole 15' due to friction, and the workpiece 9 is moved up by the hole 15'. The assembling device 1 rises and recycles the workpiece 9 to the chute 8 in accordance with the setting program of the industrial robot 3.

In addition, in the ascent process of the assembly device 1,
Since the compression spring 33 presses the rod 19 downward relative to the casing 17 through the thrust bearing 32 and the flange 20, the rod 19 is rotated in the opposite direction by the screws 30 and 31 of the rotary cam.
It descends relative to the casing 17, and the upper stopper 27 comes into contact with the upper surface 29 of the collar 28, reaching the stroke end and returning to the initial state.

Then, the cycle of fitting the next workpiece 9 into the holes 15, 15' is restarted.

It goes without saying that the embodiment of this invention is not limited to the above-mentioned embodiment. For example, a proximity switch may be provided between the casing and the rod so that when a workpiece interferes with the edge of the hole, a lamp, buzzer, etc. Various modes can be adopted, such as making it work.

In addition, as a design change, the holding device may use a magnet or solenoid to adsorb the workpiece instead of using vacuum negative pressure, and the lifting actuator may use a pinion rack mechanism driven by a motor in addition to a fluid cylinder. Of course, it is also possible.

It goes without saying that various workpieces and casings are possible.

<Effects of the invention> As described above, according to this invention, it is basically necessary to manually fit a workpiece into a hole in a block-shaped metal product such as an engine cylinder head through an extremely small fitting gap. Even without visual inspection or the like, a device with a simple structure has the excellent effect of being able to smoothly reject items in a stable posture, taking into account errors during manufacturing of the attached object or workpiece.

Therefore, the reliability of not only the jig but also the apparatus is increased, and the product yield is also improved.

The principle of the precondition is that even if interference occurs due to misalignment of the workpiece to a hole with a small fitting gap, if the misalignment is slight, the workpiece can be fitted into the hole immediately by rotating the two relative to each other. Utilizing the principle that the workpiece can be fitted, we have made it possible to continue applying force in the direction of fitting the workpiece to the rod while rotating the casing of the device and the internal rod relative to each other. As soon as it interferes with the edge of the hole, rotation starts and the fitting is immediately achieved, which is an excellent effect.

Thus, the rod can rotate and slide relative to the casing via an elastic body such as a compression spring, and a rotating cam such as a worm screw is provided between the casing and the rod. As a result, the rod starts rotating as soon as the work interferes with the hole, and furthermore, by being pressed by the elastic body, the work can be immediately fitted into the hole, which is an excellent effect.

In addition, the structure of the device is not very complicated, as it is only necessary to engage a worm, such as a worm screw, with a rod installed in the casing interposing the pressure body, and the structure is not very complicated, easy to manufacture, and maintenance is not complicated. This has the advantage of improved durability and lower initial and running costs.

[Brief explanation of the drawing]

The drawings are explanatory diagrams of one embodiment of this invention. Fig. 1 is a schematic vertical cross-sectional view of the structure, Fig. 2 is a longitudinal cross-sectional view illustrating the state of interference between the workpiece and the hole, and Fig. 3 is a schematic diagram of a specific example to which the invention is applied. FIG. 14... Attachment object, 15'... Hole, 9... Work, 21... Holding section, 19... Rod, 6... Actuator, 1... Assembly device, 17... Casing, 33... Pressure Body, 30, 31...rotating cam.

Claims (1)

[Scope of utility model registration request] In a workpiece assembling device in which a rod having a workpiece holding portion at its tip for a hole in an attached body is linked to an elevating actuator, the rod is rotatable via a resilient body with respect to a casing connected to the elevating actuator. A workpiece assembling device characterized in that the workpiece assembling device is pivotally installed to be able to move up and down and is linked via a rotating cam.