JPH0783902B2 - Pneumatic drilling tool - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention punches a workpiece such as an aluminum sash with a pin driven by air pressure.
The present invention relates to a pneumatic drilling tool called a so-called air punch that performs desired drilling.

[0002]

2. Description of the Related Art Conventionally, a pneumatic drilling tool of this type has a drilling pin 5 and a recess 6 into which the pin 5 is fitted, as shown in FIG.
A pair of gripping rods 30 and 31 formed near the tips are pivotally attached to the front end of the cylinder 1 so as to be rotatable and openable, and the rear ends of the gripping rods 30 and 31 are tapered in the front-rear direction. It is formed by facing the surface 2a, and the hole is formed in the piston 2
Is pushed to the left in the drawing by air pressure to close and drive the grip rods 30 and 31 in contact with the tapered surface 2a of the piston 2, and the pin 5 and the recess 6 cause the workpiece (not shown). No.) was clamped and sheared. Incidentally, reference numeral 9 in the drawing
Is an air chamber for pushing the piston 2; 10 is an air chamber for returning the piston 2; 32 is a spring for urging the tip ends of the two gripping rods 30 and 31 to open; 8 is a switching valve 21, a ball valve 19, etc. The switching valve mechanism part is shown.

[0003]

In the conventional pneumatic drilling tool described above, since the gripping rod having the pin projecting is rotated to punch the workpiece, the shearing force does not act vertically, Accurate perforation is difficult to perform, and the rotation of the gripping rods pushes the rear ends of the gripping rods inwardly by the tapered surfaces of the pistons against the biasing force of the spring mounted between the gripping rods. Therefore, there is a problem that the pinching pressure of the pin is insufficient and it is difficult to punch a hard member or a thick member. Further, since the return of the pin is performed by expanding the grasping rod by a spring mounted between both grasping rods, the pin is inserted into the work piece and cannot be removed, or the grasping rod is in the original state. There was a problem that there is a risk that it will not return to. The present invention aims to solve these conventional problems.

[0004]

The pneumatic drilling tool of the present invention comprises a cylinder in which a return piston provided inside slides in the axial direction by air pressure, and a cylinder mounted on the tip of this cylinder. The head and the jaw are provided so as to face each other at an appropriate interval extending along the moving direction of the double-acting piston on the far side, and the head is provided along the direction orthogonal to the direction in which the interval extends. A head fitting provided with an elevating guide hole, a pin slidably arranged in the elevating guide hole, a pin provided with a rack on a side surface, and a rack provided on the pin that is connected to the return piston. A gear mechanism that meshes with the front end portion, and a link mechanism that rotates the gear when the return piston slides in the cylinder. It is an.

Further, in order to improve the protruding force of the pin, the return piston tightly fitted in the cylinder is formed in a substantially H shape in side view in which the front and rear airtight portions are projected, and both the airtight portions of the return piston are formed. A ring-shaped central partition wall is fitted in an airtight and slidable manner, and an air chamber formed by the central partition wall fixed at a predetermined position on the inner wall of the cylinder and the airtight part in front of the return piston is provided at the rear part of the cylinder. It was decided to communicate with the formed air chamber.

[0006]

In the pneumatic drilling tool of the present invention, the head fitting is provided at the tip of the cylinder.
With a space extending along the moving direction of the return piston,
The head and jaw are facing each other. When the return piston slides in the cylinder, the linear motion of the piston is converted into rotational motion by the link mechanism, and the gear provided at the tip of the link mechanism rotates.
The gear meshes with the rack on the side surface of the pin provided in the elevation guide hole provided in the head portion, and the rack is moved along the elevation guide hole by the rotation of the gear. As a result, the pin moves along the up-and-down guide hole, and the work piece inserted in the space between the head and the jaw is punched. The pin slides linearly in the up-and-down guide hole by the rack on the side surface that meshes with the gear to smoothly pierce the workpiece and to smoothly return to the initial state.

Further, the central partition fitted to the return piston is
The piston is pushed forward by the air pressure fed to the air chamber formed in front of the piston, and acts to increase the protrusion force of the piston pushed out by the air pressure fed to the air chamber behind the piston.

[0008]

1 is a partially cutaway side view showing an embodiment of a pneumatic drilling tool of the present invention. As shown in the drawing, the pneumatic drilling tool of the present invention comprises a head 1'which has a vertical guide hole 3'a for a pin at the front end of a cylinder 1 into which a return piston 2 is slidably inserted, and a pin at the top. Jaw 3 "with receiving recess 6"
The head metal fitting 3 having a substantially U-shape in side view is fixed. The head 3'and the jaw 3 "of the head metal fitting 3 are opposed to each other with a space extending along the moving direction of the reciprocating piston 2 in between, and a workpiece such as an aluminum sash is inserted into the space. The elevating guide hole 3'a extends in a direction orthogonal to the extending direction of the gap between the head 3'and the jaw 3 ". A pin 5 is slidably inserted in the elevating guide hole 3'a. The piston 2 and the head fitting 3 are connected via a link mechanism 4 formed by connecting a plurality of link rods 4a, 4b, 4c, 4d. The pin 5 slidably provided in the elevating guide hole 3'a is provided with a rack 5'on its side surface, and the rack 5'is formed with a gear 4'd formed at the tip of the frontmost link rod 4d. Meshes with.

In the link rod 4d, one end side provided with a gear 4'd is rotatably attached to the head 3'of the metal fitting 3 with a shaft 29, and the other end side is a pin 27 with one end of the other link rod 4c. The other end of the link rod 4c is rotatably connected by a shaft 28 to the tip of the link rod 4a whose rear end is connected to the tip of the piston 2 to the shaft 13 and to the bottom of the head fitting 3. A pin 26 is connected to the end of the linked link rod 4b.

Further, the return piston 2 has a front portion and a rear portion, respectively, in the same manner as the conventionally known return piston.
Is airtightly fitted into the small diameter portion 1'and the large diameter portion 1 "to form an air chamber 9 for pushing out the piston 2 between the rear valve mechanism portion 8 and air for returning the piston 2 around the front portion. It is adapted to form a chamber 10.

In the figure, reference numeral 11 is a guide pin penetrating the center of the piston 2, and 12 is a ventilation path formed in the circumferential direction of the piston 2 and communicating with a center hole 11 'of the guide pin 11. Further, 7 is a lever for driving a switching valve (not shown), and 14 is an O-ring for keeping airtightness between the piston 25 and the cylinder 1.

In the pneumatic punching device of the present invention having the above-mentioned structure, when the lever 7 is pushed down, the compressed air supplied from the air supply device (not shown) by the function of the switching valve (not shown) installed in the valve mechanism 8 Are sent into the air chamber 9 behind the piston 2. Therefore, the air pressure in the air chamber 9 increases,
Push the piston 2 to the left in the figure. At this time, the air in the front air chamber 9 is discharged to the outside through the ventilation passage 12 and the center hole 11 ′ because the center hole 11 ′ of the guide pin 11 is opened to the outside by the function of the switching valve. Therefore, the movement of the piston 2 described above is not hindered. The movement of the piston 2 pushes the link rod 4a attached to the tip of the piston 2 forward. The tip of the link rod 4a has one end of the link rod 4b pivotally attached to the lower part of the head fitting 3. Since it is connected to the other end, it will be pushed obliquely upward. Therefore, the front link rod 4d connected through the link rod 4a and the link rod 4c is rotated in the counterclockwise direction about the shaft 29 as indicated by the chain double-dashed line in the figure, which causes the link rod 4d to rotate. The rack 5 ', in which the gear 4'd at the tip of 4d is meshed, is pushed downward so that the tip of the pin 5 projects below the head 3'. Therefore, a workpiece (not shown) such as an aluminum sash inserted between the head 3'and the jaw 3 "of the head fitting 3
Is pinched between the pin 5 and the recess 6 provided in the jaw 3 ", and a hole corresponding to the diameter of the lower end of the pin is punched out.

Next, when the lever 7 is returned, compressed air is sent into the front air chamber 10 by the action of the switching valve, and the rear air chamber 9 communicates with the outside air. Therefore, the piston 2 moves to the right and each of the linked link rods 4a, 4b, 4
The c and 4d operate in the opposite manner to the above, and the gear 4'd pushes up the engaged rack 5'and pulls the pin 5 into the head 3 '. Therefore, the pin 5 is pulled out from the work piece, and the desired perforation is made in the work piece.

FIG. 2 shows a second embodiment of the present invention,
In this embodiment, as shown in the drawing, the piston 2 for pushing the link mechanism 4 is formed in a substantially H shape in a side view in which the airtight portions 2 ', 2 "are projected forward and backward, and is formed into a substantially ring shape fixed to the cylinder 1. The central partition 15 is fitted airtightly and slidably,
An air chamber 16 formed by the central partition 15 and the airtight portion 2 ′ on the front side and an air chamber 9 formed at the rear portion of the piston 2 are communicated with each other via a ventilation passage 17 formed in the piston 2. By doing this, when the piston 2 moves forward,
The area where the pressure acts on the piston 2 increases, and the piston 2 is pushed out with a larger force.

Next, the operation of the pneumatic drilling tool according to the embodiment will be described with reference to FIG. 1. First, when the lever 7 is pushed down, the ball valve 1 urged by the spring 20 via the pin 18 is pressed.
9 is pushed down and the upper vent 23 is opened. Therefore, the compressed air supplied from the compressed air supply device (not shown) connected to the air supply port 33 passes through the upper vent passage 25 of the switching valve 21 from the ventilation port 23 and flows into the air chamber 9 at the rear of the piston 2. , Also flows into the air chamber 16 in the front through the air passage 17 formed in the piston 2, and pushes the piston 2 to the left in the drawing by the air pressure of both air chambers 9, 16. Therefore, the pin 5 connected to the piston 2 via the link mechanism 4 is pushed downward similarly to the above-mentioned embodiment, and punches a workpiece to form a hole. At this time, since the piston 2 is pushed by the air pressure of the front and rear air chambers 16 and 9 as described above, the output of the piston 2 calculated by air pressure × area is smaller than that of the conventional one.
The number is significantly increased, and it is possible to punch a harder material or a work piece having a thick width.

After punching a predetermined hole in this way,
When the lever 7 is returned, the ball valve 19 biased by the spring 20
Rises and closes the vent hole 23, the compressed air sent in flows from the lower vent passage 24 toward the switching valve 21 and pushes up the switching valve 21 against the urging force of the spring 22 to form the guide pin 11. The air chamber 10 formed by the central partition wall 15 and the rear airtight portion 2 "through the central hole 11 'and the ventilation passage 12
Pour into. At this time, at the same time, the switching valve 21 opens the upper ventilation passage 25, which communicates with the air chamber 9 behind the piston 2, to the outside, so that the air in both air chambers 9 and 16 moves to the outside as the piston 2 moves. The piston 2 is pushed out and moves to the right in the figure. Therefore, the pin 5 connected to the piston 2 via the link mechanism 4 is drawn into the head portion 3'of the head fitting 3 by the completely opposite operation, and the work is completed.

As described above, in the pneumatic drilling tool of the present invention,
The lever is driven to move the pin in and out, and a desired hole is formed in the workpiece.

[0018]

[0019]

As described above, in the pneumatic drilling tool of the present invention, since the reciprocating movement of the piston is transmitted to the pin through the link mechanism, the rack and the gear, the pin is in the reciprocating movement direction of the piston. It can move smoothly in a direction orthogonal to the direction to perform accurate drilling, and there is no fear that the pin will not return or will not come off from the workpiece. as a result,
The pneumatic drilling tool of the present invention has improved usability and significantly improved efficiency of drilling work.

When the piston is provided with a central partition,
Since the pin is driven to project with a larger force, punching of harder materials and thicker workpieces can be performed without increasing the size of the device and hindering usability, expanding the usable range and working. It has many excellent effects that make it more reliable.

[Brief description of drawings]

FIG. 1 is a cutaway side view of a main part of a first embodiment.

FIG. 2 is a vertical side view of a second embodiment.

FIG. 3 is a vertical sectional side view of a conventional example.

[Explanation of symbols]

 1 Cylinder 2 Piston 2 ', 2 "Airtight part 3 Head metal fitting 4 Link mechanism 4'a Rack 5 pin 5'd Gear 6 pin receiving recess 7 Lever 9,10,16 Air chamber 11 Guide pin 15 Central bulkhead

Claims (2)

[Claims] 1. A cylinder in which a return piston provided inside slides in the axial direction by air pressure and a tip end portion of this cylinder are attached, and the return piston is provided on the far side of the cylinder along the moving direction of the double acting piston. A head and a jaw are provided so as to face each other with an appropriate gap between them, and a head fitting having a lifting guide hole in the head along a direction orthogonal to the direction in which the gap extends, and a lifting guide. A pin, which is slidably disposed in the hole, is provided with a rack on its side surface, and a gear, which is connected to the return piston and meshes with the rack provided on the pin, is provided at the tip end. A pneumatic drilling tool comprising: a link mechanism in which a gear is rotated by a moving piston sliding in a cylinder. 2. A return piston is formed in a substantially H shape in side view in which front and rear airtight portions are projected, and a ring-shaped central partition wall is airtightly and slidably fitted between the both airtight portions of the return piston. The air chamber formed by the central partition wall that is airtightly fixed at a predetermined position on the inner wall of the cylinder and the airtight portion in front of the return piston is communicated with the air chamber formed in the rear portion of the cylinder. The pneumatic drilling tool according to claim 1.