JPH0398774A - Key striking device for forging machine - Google Patents

Abstract

PURPOSE:To allow a key to be struck under a specified regulation by performing the relative positioning of a stroke rod and a piston hammer for advancing the stroke rod toward the key with air pressure by a cylinder and a rod holder. CONSTITUTION:Air in an air tank 31 is led into a cylinder 16 through a first port 18 by a first change-over valve 30 so as to move a piston hammer 28 in the cylinder 16 toward a forging machine. The hammer 28 then collides against the rear end of a stroke rod 26, thus providing a key with impact force through the rod 26 and a jig 22 at the front end of the rod 26. In this case, the relative positioning of the piston hammer 28 and stroke rod 26 is performed by the cylinder 16 and a rod holder 21, and the piston hammer 28 is struck against the stroke rod 26 without missing the aim. In this stroke, the air in the air tank 31 is led also into the operating cylinder 54 of a rapid exhaust valve 51, so that through its operating piston, a valve body is moved in the receding direction from the rod holder 21, thus releasing an air passage 52a communicated with a second port.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used for driving in and out of keys for fixing upper and lower molds or soap blocks of a forging machine. This invention relates to a key striking device for a forging machine.

[Prior Art] A forging machine 1 such as an air stamp hammer shown in FIG.
The machine is equipped with an upper mold 3 attached to the lower end of a ram 2 that is raised and lowered, and a lower mold 5 attached to a soap block 4, and a metal material is forged between these upper and lower molds 3 and 5. These molds 3, 5 and soap lock 4 are fixed by driving a key 6 into one side of each mold. Of course, the key 6 is driven into the forging machine 1 from the front or rear side.
This may be longer or shorter than the thickness of the molds 3, 5 or the soap block 4 in the front-rear direction. In FIG. 8, 7 is a bolt for connecting the left and right frames 1b to the base 1a of the forging machine 1, and 8 is a hole opening in both the front and rear end surfaces of the soap block 4.

The key 6 for fixing the mold 3.5 and the soap lock 4 is driven in and removed by suspending a push rod horizontally from a suitable support member on the ceiling and using the push rod like a bell striker. The operation is done by striking the key through a jig with its tip.

However, when such manual operation is performed, the workability is poor and skill is required, and it is difficult to hit the keys accurately. Furthermore, if the strike is performed incorrectly, the energy of the strike may cause the thrust rod to move freely and easily hit the worker, resulting in a very high risk of work.

Therefore, a key striking device that does not require manual operation is conventionally known. This device is used by being fixed to the fork of a forklift truck, and has a piston rod included in an air cylinder mechanism that protrudes from the cylinder, and a jig is attached to the tip of the rod. Therefore, by retracting the piston and rapidly advancing the piston using pneumatic pressure, the piston and jig are used as hammers to strike the key, thereby making it possible to drive in and remove the key.

[Problems to be Solved by the Invention] However, with such a conventional key striking device, it is undeniable that the forklift truck moves somewhat due to the reaction force at the time of striking, and the key is driven in by the striking force. When making the next impact, it is necessary to advance the forklift truck toward the forging machine, and each time the forklift truck must be aligned so that the center of the jig matches the center of the key. In this case, since there is no means for regulating the positions of the key and the tip of the piston rod relative to each other, it is difficult to aim the piston rod with respect to the core of the key. Therefore, with the conventional device, there is a problem in that it requires a lot of time and effort for striking, and the workability is poor. Moreover, since a forklift truck is used, an operator of the key striking device is required together with the driver of the forklift truck, which requires a large amount of manpower.

Moreover, since a forklift truck is used, sufficient space is required around the forging machine to accommodate the truck, and if such space cannot be secured,
There was also the problem that the device could not be applied.

An object of the present invention is to provide a key striking device for a forging machine that can strike a key with high workability and strong force without requiring much manpower or space.

[Means for Solving the Problems] In order to achieve the above object, in the key striking device for a forging machine of the present invention, a piston hammer is disposed in a cylinder whose axes are aligned in the front and back direction of the forging machine. The air tank is connected to a first port provided at the rear end of the cylinder via a first switching valve that is movably accommodated and moves the hammer back and forth in the front and rear directions, and a rod holder is connected to the front end of the cylinder. The rod holder movably supports a striking rod that protrudes from its front end and contacts the end face of the key of the forging machine via a jig and collides with the piston hammer from behind. a housing provided with a stopper portion for regulating the retreating position of the striking rod, having an exhaust port and an air passage communicating with a second port provided on the rod holder at a position rearward from the stopper portion; an actuating cylinder connected to the valve housing and connected to the air tank via the first switching valve; a valve body that is reciprocated by an actuating piston in the actuating cylinder to open and close the air passage; A quick exhaust valve having a return port formed in communication with the air passage and connected to the air tank via the first switching valve is disposed on the front end side of the cylinder, A mooring cylinder mechanism having a piston rod protruding toward the rear of the cylinder is connected to the cylinder, and this mechanism and the air tank are communicated via a second switching valve that reciprocates the piston rod in the front-rear direction. A cable connecting member is connected to the tip of the piston rod, and each of the plurality of tethering cables, the tip of which is connected to the hook of the forging machine during the key striking operation, is connected to the cable connecting member. This is what I did.

[Function] This key striking device is designed to operate a forging machine by bringing a jig attached to the front end of the striking iron whose retracted position relative to the rod holder is regulated by a stopper into contact with the end face of the key of the forging machine. placed horizontally on the front or back side of the In this arrangement, the plurality of tethering cables are held in tension by hooking their tips onto the hooks of the forging machine. This tensioning is performed by operating the second switching valve to guide the air in the air tank to the mooring cylinder mechanism. As a result, the piston rod of the cylinder mechanism moves in a direction away from the forging machine, so each tethering cable is held tensioned. Then, the entire key striking device receives a force from the forging machine side, and the state of contact between the jig and the key is maintained.

In the above arrangement, air from the air tank is guided into the cylinder through the first port via the first switching valve, and the piston hammer in the cylinder is moved toward the forging machine. The hammer then collides with the rear end of the striking rod and applies striking force to the key via this rod and the jig at its front end.

In this case, since the cylinder and rod holder relatively position the piston hammer and the striking rod,
The piston hammer can collide with the striking rod without changing its aim. Furthermore, during this impact, the air in the air tank is also guided to the actuation cylinder of the quick exhaust valve, and the valve body moves away from the rod holder via the actuation piston, causing the air to communicate with the second port. open the road. Therefore, the air in front of the piston hammer in the cylinder is quickly exhausted to the atmosphere through the second port and the quick exhaust valve, and the movement of the piston hammer can be minimized from being braked by the air in the front.

Then, since the entire key striking device is moved toward the forging machine side by the force that continues to be applied to the entire key striking device by the mooring cylinder mechanism described in Section 7, in proportion to the movement of the key due to the above-mentioned impact, the above-mentioned The state of contact between the jig and the key is still maintained. Next, by switching the first switching valve,
The actuating piston of the quick exhaust valve is moved toward the rod holder to close the air passage of this valve and guide the air from the air tank into the cylinder through the return port and the second port. As a result, the piston hammer in the cylinder is returned away from the striking rod, and then the first switching valve is switched again to strike the key. The key can be driven in or extracted by repeating the above-mentioned blows as many times as necessary.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 8.

Reference numeral 11 in FIG. 6 is a lifter that can raise and lower the pedestal 12 by operating a pedal or the like, and this lifter has wheels 13 and is movable. A key striking device 14 is detachably connected and supported on the upper surface of the pedestal 12.

This striking device 14 will be explained below. Reference numeral 15 in FIGS. 1 to 3 denotes a base that is elongated along the front-rear direction of the forging machine (numeral 1 in FIG. 8), and a cylinder 16 is attached to the top surface of the base. The cylinder 16 includes a cylinder end member 17 attached to its rear end (the end farthest from the forging machine 1). This member 17 has a first port 18
is opened, and the end plate 17 of this end member 17 is opened.
A cushioning material 19 is attached to the inner surface.

In addition, 20 in FIG. 1 is a lock nut, and 15a in FIG. 2 is a hanging ring.

A rod holder 21 is connected to the front end of the cylinder 16 (the end closer to the forging machine 1). This holder 21 has a second port 22 that communicates with the inside of the cylinder 16, and an exhaust hole 23 that is located on the front end side and communicates with the inside of the rod holder 21. A cylindrical slide bearing 25 is attached to the center of a holder end member 24 that the rod holder 21 has at its front end.

A striking rod 26 is housed in the rod holder 21 at a position in front of the second port 22 .

The rear end portion of this rod 26 has a larger diameter than the other portions, and this portion slides along the inner circumferential surface 21a of the rod holder 21. A front end portion of the striking rod 26 slidably passes through the sliding bearing 25 and projects from the front end of the rod holder 21 . 2lb in Figure 1 is
It consists of a stepped part provided inside the rod holder 21 to engage with the rear end of the striking rod 26 and regulate the retreating position of the rod 26 (the position moved most rearward with respect to the rod holder 21). This is the stopper part.

A jig 27 is removably fitted to the protruding front end of the striking rod 26, and this jig 27 is attached to the key 6 of the forging machine 1.
It is designed to come into contact with the tip of the Note that if the end of the key 6 protrudes beyond the front or rear surface of the molds 3 and 5, for example, a jig having a groove in the tip that fits into the end of the key 6 is used. Furthermore, if the end of the key 6 is recessed from the front or rear surface of the molds 3 and 5, for example, a jig having a protrusion at the tip that comes into contact with the retracted end of the key 6 is used. Ru.

A piston hammer 28 is movably housed within the cylinder 16. This hammer 28 collides with the rear end of the striking rod 26 when it moves forward.

Further, a first switching valve 30 is attached to the rear end of the cylinder 16, and the inside of the cylinder 16 is communicated with an air tank 31 via this valve 30. The air tank 31 is mounted on a cover 32 that covers most of the cylinder 16 and is provided on the base 15. In addition, in FIG. 1, 33 is an on-off valve, 34 is a pressure regulating valve, and 35 is a pressure gauge.
Air is appropriately replenished into the air tank 31 through these.

As shown in FIG. 1, the first switching valve 30 includes a neutral valve chamber 36 having an annular shape, and a neutral valve chamber 36 formed on both sides of the neutral valve chamber 36. J1
A sleeve 44 having through holes 40 to 43 is attached inside a valve housing 39 having a valve chamber 37 and a second valve chamber 38, and a valve body 45 is slidably provided inside this sleeve 44. The passage hole 40 communicates with the neutral valve chamber 36 , the passage hole 41 communicates with the first valve chamber 37 , and the passage hole 42 , 43 communicates with the second valve chamber 38 . The through hole 42 is smaller in shape than the through hole 43.

The valve body 45 is reciprocated via the operating handle 46, and when moved forward, the neutral valve chamber 36 is communicated with the first valve chamber 37 through the through holes 40, 41, and the neutral valve chamber 36 is communicated with the first valve chamber 37 through the through holes 40, 41, and when it is moved forward, the valve body 45 is moved back and forth. When the neutral valve chamber 36 is moved toward
The second valve chamber 38 is communicated through the through holes 40, 42, 43. Moreover, the neutral valve chamber 36 is connected to the pipe 4
7 to the air tank 31, and the first valve chamber 37 is communicated with the first port 18 of the cylinder 16.

A quick exhaust valve 51 is attached to the front outer surface of the cylinder 16. As shown in FIG. 4, the exhaust valve 51 includes a valve seat body 52, a fixed cylinder body 53 fixed to the valve seat body 52, and an operating cylinder 54 fixed to the cylinder body 53.
and an operating piston 55 housed within this cylinder 54.
and a valve body 56 which is movably provided through the actuation cylinder 54 and has an actuation piston 55 attached to one end thereof.
, a coil spring 57 that biases the valve body 56 , and a movable cylinder 58 fitted to the outside of the fixed cylinder 53 .

The valve seat body 52 and the fixed cylindrical body 53 form a valve housing, and the air passage 52a of the valve seat body 52 is connected to the piston 1.
The valve body 5 is connected to the second port 22 of the valve body 5.
6 to be opened and closed. coil spring 57
In order to stabilize the closed state of the valve body 56, the valve body 56 is pressed against the valve seat body 52. The valve seat body 52 is formed with five return ports communicating with the air passage 52a, and these ports 59 are connected to the second valve chamber 3 of the first switching valve 30.
It is connected to 8.

The actuating cylinder 54 has ports 54a. 54b is provided. The port 54a communicates with the second valve chamber 38 of the first switching valve 30. The port 54b communicates with the first valve chamber 37 of the first switching valve 30.

The fixed cylindrical body 53 and the movable cylindrical body 58 are provided with exhaust ports 53a at predetermined intervals, respectively. 58a, and the communication area thereof is adjusted by rotating the movable cylinder 58.

The adjustment position is fixed by moving the movable cylinder 5 as shown in FIG.
This is done by tightening a screw 60 (see FIG. 4) that is threaded into the fixed cylinder 53 through an arc-shaped adjusting hole 58b.

A mooring cylinder mechanism 61 is connected to the outer surface of the cylinder 16. As shown in FIGS. 1 and 2, this cylinder mechanism 61 includes a mooring cylinder 62, a piston 63 housed in this cylinder 62, and this piston 6.
3 and a piston rod 64 connected to one end. The piston rod 64 projects toward the rear of the mooring cylinder 62, in other words, toward the direction away from the forging machine 1.

As shown in FIG. 7, ports 62a and 62b that the connecting cylinder 62 has at its front and rear ends, respectively, are communicated with the air tank 31 via a second switching valve 65 shown in FIGS. 6 and 7. ing. The second switching valve 65 allows the rear port 62b to be opened to the atmosphere when the air in the air tank 31 is guided to the front port 62a.
A switching valve is used that has a structure that opens the front port 62a to the atmosphere when the air in the air tank 31 is guided to the rear port 62b. The operating handle 66 of this switching valve 65 is shown in FIG.

As shown in FIGS. 1 and 2, a cable connecting member 67 is connected to the tip of the piston rod 64 of the cylinder mechanism 61. As shown in FIGS. This member 67 is formed by connecting a cylindrical body 70 to the center of the plate 6, which is inserted through an elongated window 68 (see FIG. 6) provided in the cover 32 along the front-rear direction, for example. The cylindrical body 70 is fitted onto the outer periphery of the cylinder 16 so as to be movable in the front and rear directions using the cylindrical body 70 as a guide. One end of a tethering cable 71 is connected to both left and right ends of the plate 69 protruding from the window 68, respectively.

For example, a chain is used as the tether 71. The tips of these tethering cables 71 are connected to the forging machine 1 by using the bolts 7 of the forging machine 1 as a hook part, or by inserting a round bar into the hole 8 of the forging machine 1 and using this as a hook part. It has become.

Next, the operation of the key striking device 14 having the above configuration will be explained.

First, the key striking device 14 is arranged horizontally on the front or rear side of the forging machine 1. A jig 27 is attached to the front end of the striking rod 26, and the key striking device 14 is operated by operating the lid 11. The height of the lifter 11 is adjusted so that the center matches the core of the key 6 of the forging machine 1. Note that if the lifter 11 cannot be used, the key striking device 14 can be removed from the lifter 11 and the hanging rings 15 provided at both front and rear ends of the device 14 can be used.
The height may be adjusted by suspending the key striking device 14 from a chain block of a hoist or the like using the key a. After this adjustment, the ends of the pair of left and right tethering cables 71 are hooked onto the hooks of the forging machine 1, and are stretched to bring the jig 27 into contact with the end face of the key 6.

To tension each mooring cable 71, rotate the operating handle 66 of the second switching valve 65 in the forward direction (see FIG. 6). This is achieved by guiding the air in the air tank 31 to the port 62a of the cylinder 62 of the mooring cylinder mechanism 61.

In other words, since the piston rod 64 of the cylinder mechanism 61 moves backward away from the forging machine 1, the accompanying movement of the cable connecting member 67 causes each mooring cable 71 to move backward.
is set up. Therefore, the cylinder mechanism 61 presses the entire key striking device 14 toward the forging machine 1, and maintains the contact state between the jig 27 and the key 6. Note that the cable connecting member 67 has a cylindrical body 70, and the lower part of the cylindrical body 7o supports the cylinder 16 from below. The device 14 can be stabilized by preventing rotation about the contact point.

After the key striking device 14 is set in the forging machine 1 as described above, the operating handle 46 of the first switching valve 3o is moved from the neutral position to the striking (see FIG. 6) position. Then, the valve body 45 is moved rearward (to the left in FIG. 1), and the neutral valve chamber 36 communicating with the air tank 31 and the first
It communicates with the valve chamber 37. Therefore, the air tank 3L
The pressure within is supplied through the first switching valve 30 into the cylinder l6 through its first port 18, and the same pressure is supplied through the first switching valve 30 into the actuating cylinder 54 of the quick exhaust valve 54. through its port 54b. At this time, the air discharged from the port 54a of the operating cylinder 54 passes through the second valve chamber 38 of the first switching valve 30, passes through the communication holes 42 and 43 through the inside of the valve body 45, and is exhausted to the outside of the valve housing 39. Ru.

Then, the piston hammer 28 in the cylinder 16 becomes
The pressure introduced into the cylinder 16 moves it forward, that is, in the direction of the forging machine. At the same time, the operating piston 55 of the quick exhaust valve 51 quickly moves upward in FIG. 4 along with the valve body 56 against the force of the coil spring 57.
moves away from the valve seat body 52 and opens its air passage 52a. Therefore, the space in front of the piston hammer 28 in the cylinder 16 is connected to the outside of the quick exhaust valve 51 through the second port 22 and the air passage 52a, and through the exhaust ports 53a and 55a, which are in communication with each other. Cylindrical body 5
3.

Therefore, the air in front of the piston hammer 28 in the cylinder 16 flows through this communication path to the cono hammer 28.
Since the air is quickly exhausted outside the cylinder 16 as the piston hammer 8 moves forward, the movement of the piston hammer 28 is rarely hindered by this front air.

In addition, since the air exhausted from the cylinder 16 is released into the atmosphere as described above, compared to the case where the exhaust air is led to the first switching valve 30 etc. via piping, there is no piping resistance and the air can be removed from the cylinder 16. It is extremely easy to expel air.

As described above, the piston hammer 28, which is not subjected to the air brake action, collides with the rear end of the striking rod 26 at high speed, and applies a striking force to the key 6 via this rod 26 and the jig 27 at its tip. Furthermore, the air within the rod holder 21 is exhausted to the atmosphere through the exhaust hole 23 as the striking rod 26 moves forward.

In the above striking, the cylinder 16 and the rod holder 21 position the piston hammer 28 and the striking rod 26 relative to each other, so that the cylinder 16 and the rod holder 21 aim at the striking rod 26 which is in contact with the key 6 via the jig 27. It is possible to cause the piston hammer 28 to collide without making any difference.

Next, when the operating handle 46 of the first switching valve 30 is returned from the forward position to the return position (see FIG. 6), the valve body 45 is moved forward (to the right in FIG. 1), and the air tank 31 is moved forward (to the right in FIG. 1).
The neutral valve chamber 36 and the second valve chamber 38 are communicated with each other, and the valve body 45 moves away from the communication hole 41 to open it. Therefore, the pressure in the air tank 31 is supplied via the first switching valve 30 into the operating cylinder 54 of the quick exhaust valve 51 through its port 54a, and the valve body 56
closes the ventilation passage 52a. Note that the air discharged from the port 54a of the actuating cylinder 54 is
The air is exhausted through the first valve chamber 37 of the switching valve 30, through the communication hole 41, through the inside of the valve body 45, and out of the valve housing 39. At the same time, the pressure inside the air tank 3 is increased by the first switching valve 30.
are led to five return ports of the rapid exhaust valve 51 through the. At the same time, since the space behind the piston hammer 28 in the cylinder 16 is communicated with the atmosphere through the communication hole 41, the first valve chamber 37, and the first port 18, the air passage from the port 59 The piston hammer 28 is returned until it comes into contact with the buffer material 19 by the air pressure of the air tank 31 introduced into the cylinder 16 through the second port 22 of 52a1.

Then, the operation handle 46 is operated again to perform the next blow. That is, by repeatedly hitting the key 6 as described above a necessary number of times, the key 6 can be pulled out or driven in.

When removing the key 6, if the key 6 starts to come out, it is preferable to reduce the impact force so that the key 6 does not suddenly pop out. In this case, the impact force can be adjusted by stopping the /% handle 46 just before moving it forward when moving the operating handle 46 of the first switching valve 30 forward. In this way, the amount of air flowing into the cylinder 16 per unit time can be reduced.

Alternatively, this can be achieved by rotating the movable cylindrical body 58 of the rapid exhaust valve 51 to reduce the communication area of the exhaust hole 5 3 a s 5 8 a, and applying an air brake effect to the movement of the piston hammer 28.

Although the key 6 is moved in accordance with the hitting operation described above, the state of contact between the jig 27 and the key 6 is still maintained. In other words, since the pressure of the air tank 31 continues to be applied to the cylinder 62 of the mooring cylinder mechanism 61 through its port 62a,
The piston 63 and the piston rod 64 are moved rearward by the same amount as the key 6 moved by the blow. As a result, the mooring cylinder mechanism 61 continues to apply force to the entire key striking device 14 in the direction of the forging machine 1, so that the entire key striking device 14 is moved toward the forging machine 1 side.

Of course, at this time, the striking rod 26 retreats relative to the rod holder 21, but this retreat
The large diameter portion of the striking rod 26 comes into contact with the first stopper portion 2lb, whereby the striking rod 26 is stopped. That is, as described above, the contact between the jig 27 and the key 6 is maintained.

Therefore, according to this key striking device 14, there is no need to reposition the key 6 and the device every time the key is struck, so that the key 6 can be struck with high workability and with a large force. Since there is no need to use a forklift truck, the key 6 can be struck without requiring much manpower, and the key 6 can be struck without requiring much space around the forging machine 1. I can do it.

The present invention is not limited to the above embodiment. For example, the movable cylinder 58 of the quick exhaust valve 51 may be omitted. Further, the lifter 11 may be omitted.

[Effects of the Invention] The key striking device of the present invention includes the cylinder, the piston hammer, the rod holder, the striking rod, the first switching valve, and the air tank. A piston hammer that advances the rod in one direction by air pressure is positioned relative to the piston hammer, and the key can be struck under this regulation.

In addition, a quick exhaust valve is provided to rapidly exhaust the air inside the cylinder to the atmosphere, thereby reducing the need for air brake action on the piston hammer, allowing the key to be struck with a strong force. Furthermore, a mooring cylinder mechanism, a cable connection member,
By providing the tethering cable and the second switching valve, the entire striking device can be moved toward the forging machine following the movement of the key based on the above-described striking, and the state of contact between the striking rod and the key can be maintained.

Therefore, according to the device of the present invention, there is no need to reposition the key and the device each time the key is struck, so the key can be struck with high work efficiency, and there is no need to use a forklift truck. The key can be struck without requiring any manpower, and the key can be struck without requiring much space around the forging machine.

[Brief explanation of drawings]

1 to 7 show an embodiment of the present invention, FIG. 1 is a longitudinal side view of the entire striking device, FIG. 2 is a plan view of the entire striking device, and FIG. 3 is a front view of the entire striking device. , FIG. 4 is a longitudinal side view of the quick exhaust valve, FIG. 5 is a plan view of a part of the quick exhaust valve, FIG. 6 is a side view of the entire striking device, and FIG. 7 is a piping system diagram of the striking device. . FIG. 8 is a schematic front view showing a part of the forging machine. DESCRIPTION OF SYMBOLS 1... Forging machine, 6... Key 14... Key striking device, 16... Cylinder, 18... First port, 21
...Rod holder, 22...Second port, 26...
-Blowing rod, 27... Jig, 28... Piston hammer, 30... First switching valve, 31... Air tank, 51... Rapid exhaust valve, 52... Valve seat body ( Benkyo)
52a...Air passage, 53...Fixed cylinder body (valve housing) 53
a...Exhaust port, 54...Operating cylinder, 55...
Operating piston, 56... Valve body, 59... Port, 6
l...Cylinder mechanism, 64...Piston rod, 6
5... Second switching valve, 67... Cable connection member, 71...
...Tethering rope.

Claims (1)

[Claims] A piston hammer is movably housed in a cylinder disposed with its axes aligned in the front-rear direction of the forging machine, and air is supplied through a first switching valve that reciprocates the hammer in the front-rear direction. The tank is connected to a first port provided at the rear end of the cylinder, and a rod holder is connected to the front end of the cylinder, and a jig is attached to the end surface of the key of the forging machine by protruding from the front end of the rod holder. The rod holder movably supports a striking rod that touches the striking rod from behind and that the piston hammer collides with from behind; the rod holder is provided with a stopper portion for regulating the retreating position of the striking rod; a valve housing having a ventilation passage communicating with a second port located rearward of the stopper portion; and an actuation cylinder connected to the valve housing and connected to the air tank via the first switching valve. a valve element that is reciprocated by an operating piston in the operating cylinder to open and close the air passage; A quick exhaust valve having a return port connected to the cylinder is disposed on the front end side of the cylinder, and a mooring cylinder mechanism having a piston rod protruding toward the rear of the cylinder is connected to the cylinder. , This mechanism and the air tank are communicated via a second switching valve that reciprocates the piston rod in the front-rear direction, and a cable connecting member is connected to the tip of the piston rod, so that when the key is struck, the tip is connected to the air tank. A key striking device for a forging machine, characterized in that a plurality of tethering cables, each of which is connected to a hook part of the forging machine, are each connected to the cable connecting member.