JP3011436U - Hydraulic cylinder - Google Patents

Abstract

(57) [Abstract] [Purpose] Equipped with a steady rest mechanism and a whirl stop mechanism, it is small in size, simple in structure, low in cost, and can be used for driving punches of press working machines. Provided is a fluid pressure type cylinder having accuracy and durability. [Construction] A tubular bearing 27 is provided on the tube projection 25 of the tube 3. An insertion hole 31 is formed in the head protrusion 29 formed on the head 21. The guide shaft 33 is rotatably inserted in the bearing 27 of the tube protrusion 25, and the small diameter portion 35 is inserted in the head protrusion 29. A nut 39 is attached to the small diameter portion 35,
The guide shaft 33 is fixed to the head protrusion 29. A return spring 41 is fitted on the guide shaft 33,
A spring receiver 43 is fitted to the rear end portion of 3. A nut 45 is attached to the small diameter portion 37, and the spring receiver 4
3 is retained.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic cylinder equipped in a press machine or the like, and more particularly to a hydraulic cylinder used for driving a punch or lifting a work.

[0002]

[Prior art]

 In a press machine, most cylinders that use fluid pressure such as hydraulic pressure or pneumatic pressure are used to drive punches for shearing, bending, forming, etc. in a direction other than the vertical direction, for example, in the horizontal direction or diagonal direction. It is not used, and is only slightly used in work lift-up devices and transfer devices. Pneumatic cylinders are said to be difficult to use because of the large amount of thrust required for cylinders used for press working and the incompressibility of volume. On the other hand, the reason why hydraulic cylinders are not used is that it is necessary to maintain the quality of pressed products, and therefore high precision is required for pressing. For example, the size of the gap between the punch and die used for shearing (drilling) must be set within the range of 5% to 10% of the thickness of the plate to be processed. When this is applied to a steel plate with a thickness of 1 mm used for automobile bodies, etc., the gap size between the punch and the die is 0.05 mm to 0.1 mm. Furthermore, in consideration of safety, it is necessary to keep the swing range of the piston rod within ± 0.03 mm to 0.04 mm.

[0003]

[Problems to be solved by the device]

 However, with the accuracy of the hydraulic cylinder specified in JIS, B8354, for example, it is impossible to suppress the range of deflection of the piston rod within the above range. Furthermore, considering the magnitude of the impact and eccentric load applied to the hydraulic cylinder during press working, the JIS type cylinder that is generally commercially available has too low strength to be used for press working. When a hydraulic cylinder is used for press working, it is necessary to provide a piston rod anti-rotation mechanism so that the punch always keeps the correct posture with respect to the work. However, the anti-rotation mechanism, which also functions as a mechanism for obtaining the precision capable of press working, becomes quite large and complicated. For example, there is an example in which a hydraulic cylinder is used for a work lift-up device.However, even if a piston rod rotation stop mechanism with lower accuracy than that of press working is required, the rotation stop mechanism is There is a problem in that it becomes considerably large and complicated, and the cost becomes high. Therefore, it is not practical to provide a cylinder equipped with such a rotation stopping mechanism in a press working machine, particularly in a die, to perform press working.

In addition, when using a general double-acting type cylinder, two piping hoses for supplying the pressurized liquid and the like to the tube are required. Further, the number of packings for preventing pressure leakage increases, and the total length of the cylinder becomes longer. Therefore, when mounting the double-acting type cylinder on a press machine, there is a problem that space restrictions become large. The present invention has been made by paying attention to the above-mentioned conventional problems, and is equipped with a steady rest mechanism and an anti-rotation mechanism, is small in size, has a simple structure and is low in cost, and punches for press working machines and the like. It is an object of the present invention to provide a hydraulic cylinder that can be used for driving a vehicle and has high accuracy and durability.

[0005]

[Means for Solving the Problems]

 The invention according to claim 1 is a hydraulic type having a tube, a piston accommodated in the tube, a piston rod connected to the piston, and a port for supplying a pressurized liquid for driving the piston rod in a traveling direction. A liquid characterized by comprising a head integrally formed with the tip of the piston rod, and a return spring for urging the piston rod provided outside the tube in the backward direction in the cylinder. It is a pressure cylinder.

According to a second aspect of the present invention, in the first aspect, the head projection formed on the head, the tube projection provided outside the tube and provided on the tip side of the tube, and the head projection are provided. The tube projection includes a guide shaft fixed and slidably inserted into the tube projection, and a spring receiver attached to a rear end of the guide shaft, and a return spring fitted to the guide shaft. And a spring receiver, which is a hydraulic cylinder.

A third aspect of the present invention is the hydraulic cylinder according to the second aspect, which is provided with a plurality of sets of a head protrusion, a tube protrusion, a spring receiver, a guide shaft, and a return spring.

[0008]

[Action]

 According to the present invention, when the pressurized liquid is supplied from the port, the piston is pushed and the piston rod is driven in the traveling direction. Then, a tool such as a punch attached to a head formed on the piston rod is driven to press the work. Then, when the pressurization of the pressurized liquid is released, the piston rod is biased in the backward direction by the elastic force of the return spring, and the piston is returned while pushing back the pressurized liquid.

Further, if the head projection, the tube projection and the guide shaft are provided, the piston rod is guided by the tube projection and the guide shaft, the deflection of the piston rod is suppressed, and the rotation is prevented. Furthermore, if a plurality of sets of head projections, tube projections, spring receivers, guide shafts and return springs are provided, it becomes possible to more reliably prevent the piston rod from swinging and turning.

[0010]

【Example】

 A hydraulic cylinder 1 as a hydraulic cylinder according to an embodiment of the present invention will be described with reference to the drawings. Reference numeral 3 indicates a tube, a rod case 5 is attached to the tip end of the tube 3, and a head case 7 is attached to the rear end. A head oil port 11 is formed in the head case 7. The air vent hole 13 communicating with the port 11 is closed by a screw (not shown).

A piston 15 is slidably accommodated in the tube 3, and a packing 17 is provided in the piston 15. A piston rod 19 is connected to the piston 15 and is fixed by a bolt 18. The tip of the piston rod 19 projects from the rod case 5, and a head 21 is integrally formed at the tip of the piston rod 19. The head 21 is formed in a plate shape, and a knock hole 23 is formed in the front surface of the head 21.

Tube projections 25 are formed on both left and right sides of the tip of the tube 3, and the tube projections 25 are provided with cylindrical bearings 27. A head projection 29 is formed on the head 21, and the head projection 29 is provided corresponding to the tube projection 25. An insertion hole 31 is formed in the head protrusion 29. Reference numeral 33 indicates a guide shaft, and a small diameter portion 35 is formed at the tip end portion of the guide shaft 33, and a small diameter portion 37 is formed at the rear end portion thereof. Male threads are formed on the peripheral surfaces of the small diameter portions 35 and 37.

The guide shaft 33 is rotatably inserted in the bearing 27 of the tube protrusion 25, and the small diameter portion 35 is inserted in the head protrusion 29. A nut 39 is attached to the small diameter portion 35, and the guide shaft 33 is fixed to the head protrusion 29. A return spring 41 is fitted to the guide shaft 33, and a spring receiver 43 is fitted to the rear end of the guide shaft 33. A nut 45 is attached to the small diameter portion 37 to prevent the spring receiver 43 from coming off. Therefore, the return spring 41 is provided between the tube protrusion 25 and the spring receiver 43. The contact length of the return spring 41 is set longer than the effective stroke of the hydraulic cylinder 1. A mounting plate 47 is provided on the tube 3, and a mounting hole 48 is formed in the mounting plate 47.

As shown in FIG. 1, the hydraulic cylinder 1 is applied to a punch unit 40 for press working, and as shown in FIG. 6, the punch unit 40 for press working is mounted on a die 42 for press working. . The details will be described below. A retainer 49 is attached to the head 21 by attaching bolts, and a punch 51 is held by the retainer 49. One end of a piping hose 53 is connected to the port 11 of the cylinder 1, and the other end of the piping hose 53 is connected to the upper cylinder 55. The upper cylinder 55 is provided with an upper rod 57, and when the upper rod 57 is pressed, pressurized oil is supplied from the upper cylinder 55 to the port 11 via the piping hose 53.

In FIG. 6, reference numeral 59 indicates a bolster of a press working machine, and a lower die 61 of a die is attached to the bolster 59. A work W is installed on the lower die 61. The hydraulic cylinder 1 is fixed to the lower die 61 by bolts inserted into the mounting holes 48 of the mounting plate 47. The upper cylinder 55 of one punch unit 40 is fixed on a support base 63, and the upper cylinders 55 of the other punch units 40 are fixed on a support base 63 not shown.

Reference numeral 67 indicates a slide of the press machine, and the slide 67 is adapted to move up and down. An upper die 69 of the die is attached to the slide 67. The pressing member 71 of the upper die 69 faces the upper rod 57 of the upper cylinder 55 of one punch unit 40. A pressing member 71 (not shown) faces the upper rod 57 of the upper cylinder 55 (not shown) of the punch unit 40. A pressing pad 70 is attached to the upper mold 69 by a pin 72 so as to be vertically movable. A flange 78 is formed on the pin 72, and the flange 78 prevents the pressing pad 70 from coming off the pin 72. The pressing pad 70 is biased downward by a pad spring 76.

Next, the operation of the press working die 42 will be described. When the upper die 69 descends together with the slide 67, the presser pad 70 presses the work W. In addition, the pressing member 71 presses the upper rod 57, pressurized oil is supplied from the upper cylinder 55 to the port 11 of the hydraulic cylinder 1, and the piston rod 19 along with the piston 15 resists the elastic force of the return spring 41 in the distal direction. Driven. As a result, the punch 51 is driven in the direction of the workpiece W together with the head 21, and the punch 51 punches the workpiece W.

Next, when the upper die 69 is raised together with the slide 67, the pressing of the pressing member 71 on the upper rod 57 is released. Then, the upper rod 57 is returned to its original state by the spring in the upper cylinder 55, and the pressure applied to the pressurized oil is released. When the pressure applied to the pressurized oil is released, the elastic force of the return spring 41 drives the head 21, the piston rod 19, and the piston 15 in the backward direction. Then, the pressurized oil in the hydraulic cylinder 1 is pushed back by the piston 15 and returned to the upper cylinder 55. Further, the pressing pad 70 also rises, and the pressing of the work W is released. Since the piston 15 is retracted by the return spring 41 in this way, the hydraulic cylinder 1 can be of a single-acting type. Therefore, the number of piping hoses and packings can be reduced and the length dimension can be reduced as compared with a double-acting type cylinder.

As described above, since the head 21 is guided by the guide shaft 33 and the bearing 27 of the tube projection 25, the radial movement of the piston rod 19 is restricted. Therefore, the swing of the punch 51 is suppressed, and the punch 51 can always perform processing while maintaining the correct posture. Further, since the head protrusion 29, the tube protrusion 25, the guide shaft 33, the return spring 41 and the spring receiver 43 are provided as a left and right pair, the radial movement of the piston rod 19 is surely restricted from the left and right direction. Therefore, it is possible to reliably suppress the swing of the punch 51.

Since the head 21 is formed integrally with the piston rod 19, there is no room for backlash, and the hydraulic cylinder 1 can be maintained with high accuracy. Further, since the diameter of the piston rod 19 is set larger than the diameter specified by JIS, the buckling strength of the piston rod 19 is large and the durability is high. Further, by increasing the diameter of the piston rod 19, the contact area with the rod case 5 is increased and the accuracy of the hydraulic cylinder 1 is improved.

Further, the rotation of the head 21 and the piston rod 19 is restricted by the guide shaft 33 fixed to the head protrusion 29 and inserted into the bearing 27 of the tube protrusion 25. Therefore, the guide shaft 33 fixed to the head projection 29 and inserted into the bearing 27 of the tube projection 25 serves not only as a steadying mechanism for the punch 51 but also as a whirl-stopping mechanism. Since the contact length of the return spring 41 is set longer than the maximum stroke of the cylinder 1, even if the piston 19 reaches the stroke end, the return spring 41 is not damaged and it is not necessary to provide a stroke stopper. The structure of the cylinder 1 can be simplified.

Since the return spring 41 is arranged on the side portion of the tube 3, the return spring 41 can be easily attached and detached by removing the nut 45 and the spring receiver 43. Therefore, in the blade alignment work performed prior to the processing, it is possible to easily perform the operation of manually projecting the punch 51 by the necessary stroke length. Moreover, the work can be easily performed for checking the settling of the return spring 41 and replacing the return spring 41.

As described above, the hydraulic cylinder 1 is of a single-acting type and has a structure that serves as both the steadying mechanism and the whirl-stopping mechanism of the punch 51, so that the hydraulic cylinder 1 can be downsized. Furthermore, the piston 15 can be moved forward and backward with one piping hose 53. Therefore, it becomes possible to solve the problem of space when the hydraulic cylinder 1 is mounted on the pressing die 42. Further, since the hydraulic cylinder is small, it does not hinder the work W being supplied or taken out by the robot hand.

FIG. 7 shows another embodiment in which the hydraulic cylinder 1 is applied to the lift-up device 74 for the work W. In the figure, reference numeral 75 indicates a lower mold of the mold, and the hydraulic cylinder 1 is fixed to the lower mold 75 with the head 21 facing upward. A lift-up member 77 is fixed to the head 21, and the lift-up member 77 faces the work W installed on the lower die 75. In this lift-up device 74, the head 21 moves forward together with the piston rod 19, and the lift-up member 77 pushes up the work W. Other operations are similar to those of the hydraulic cylinder 1 of the above-mentioned embodiment.

Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and the present invention is not limited even if there is a change in design within the scope not departing from the gist of the present invention. Included in the device. For example, the hydraulic cylinder may be driven not only by the upper cylinder but also by a hydraulic pump or the like. Further, in the above embodiment, the case where the hydraulic cylinder is mounted on the press working machine is shown, but it may be mounted on other machines other than the press working machine, such as a transport device and a packaging device.

Although the head protrusion 29, the tube protrusion 25, the guide shaft 33, the return spring 41, and the spring receiver 43 are provided in a pair on the left and right, these may be provided on only one side, or at three or more locations. It may be provided. Further, the knock hole 23 may not be formed, and the mounting hole 48 may not be formed.

[0027]

[Effect of device]

 As described above, according to the present invention, since the piston is retracted by the return spring, the liquid cylinder can be a single-acting type cylinder. Therefore, the number of piping hoses and packings can be reduced and the length dimension can be reduced as compared with the double-acting type cylinder. Further, since the piston rod has a steadying mechanism and a whirl-stopping mechanism, it is possible to prevent the punch from swinging and rotating. Moreover, since the steady rest mechanism also serves as the whirl stop mechanism, the cylinder can be made compact and the structure can be simple. Therefore, it is possible to solve the problem of space when mounting on a press machine or the like, and it is possible to further reduce the cost. Moreover, the hydraulic cylinder of the present invention has high accuracy and durability.

[Brief description of drawings]

FIG. 1 is a perspective view of a punch unit using a hydraulic cylinder according to an embodiment of the present invention.

FIG. 2 is a partially cutaway side view of a hydraulic cylinder according to an embodiment of the present invention.

FIG. 3 is a front view of a hydraulic cylinder according to an embodiment of the present invention.

FIG. 4 is a partially cutaway plan view of a hydraulic cylinder according to an embodiment of the present invention.

FIG. 5 is a rear view of the hydraulic cylinder according to the embodiment of the present invention.

FIG. 6 is a sectional view of a main part of a press machine equipped with a punch unit using a hydraulic cylinder according to an embodiment of the present invention.

FIG. 7 is a side view of a lift-up device using a hydraulic cylinder according to an embodiment of the present invention mounted on a press machine.

[Explanation of symbols]

 1 Hydraulic Cylinder 3 Tube 5 Rod Case 7 Head Case 11 Port 13 Air Venting Hole 15 Piston 17 Packing 18 Bolt 19 Piston Rod 21 Head 23 Knock Hole 25 Tube Projection 27 Bearing 29 Head Projection 31 Insertion Hole 33 Guide Shaft 35, 37 Small Diameter 39, 45 Nut 40 Punch Unit 41 Return Spring 43 Spring Bearing 47 Mounting Plate 48 Mounting Hole 49 Retainer 51 Punch 53 Piping Hose 55 Upper Cylinder 57 Upper Rod 59 Bolster 61, 75 Lower Die 63 Supporting Stand 67 Slide 69 Upper Die 70 Presser Pad 72 Pin 78 Flange 76 Pad Spring 71 Pressing Member 74 Lift-up Device 77 Lift-up Member

Claims (3)

[Scope of utility model registration request] 1. A hydraulic cylinder having a tube, a piston accommodated in the tube, a piston rod connected to the piston, and a port for supplying a pressurized liquid for driving the piston rod in a traveling direction. A hydraulic cylinder, comprising: a head integrally formed with a tip of the piston rod; and a return spring provided outside the tube for urging the piston rod in a backward direction. 2. The head projection according to claim 1, a head projection formed on the head, a tube projection provided outside the tube and provided on the tip side of the tube, and a tube projection fixed to the head projection. A guide shaft slidably inserted and a spring receiver attached to a rear end portion of the guide shaft, wherein a return spring is fitted to the guide shaft and is provided between the tube protrusion and the spring receiver. A hydraulic cylinder that is provided. 3. A hydraulic cylinder according to claim 2, wherein a plurality of sets of head projections, tube projections, spring receivers, guide shafts and return springs are provided.