JPH0243666Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a reciprocating pneumatic tool that is mainly suitable for filing and sawing operations that require long strokes.

[Prior art and its problems]

A large number of reciprocating pneumatic tools of this type have been developed in the past, but most of them are used for chipping work such as concrete with a chisel attached as a tool, and the stroke of the piston rod is relatively short. The switching valve that switches the reciprocating motion is not mechanically fixed to the piston rod.
Since pressurized air is injected into the base end of the piston rod and the energy is used as inertial energy to cause reciprocating movement, problems such as it cannot be used for file work or saw work that requires a stable long stroke. It had a point.

[Means to solve problems]

The present invention was devised as a result of research in view of the above-mentioned problems.The piston is fixed to the piston rod and a switching valve is provided around the piston so that it can be slid at regular intervals. There is a fixed time difference between the reciprocating movement of the piston rod and the reciprocating movement of the switching valve, and the switching valve is forcibly operated by the piston rod. The exhaust port and the double-acting switching valve exhaust port are alternately vented to either one of them, and either one of the switching valve exhaust ports and the air supply passage are connected to one of the cylinder vents. The energy of the compressed air is directly replaced as the kinetic energy of the reciprocating motion of the piston and piston rod, so the stroke of the piston rod can be lengthened and stable power can be provided, thereby solving the above-mentioned problems.

[Structure of the idea]

The piston rod is installed inside the main casing,
A piston is fixed to the piston rod, and a switching valve is provided around the piston so that it can be slid at regular intervals,
An air chamber and a valve chamber are respectively formed in the main body casing, and a forward cylinder vent and a backward cylinder vent are respectively bored into the air chamber, and the cylinder is communicated with an exhaust passage provided in the main body casing. An exhaust port is provided, and a switching valve air supply port, a forward switching valve exhaust port, and a backward switching valve exhaust port are provided in the valve chamber, and a forward air supply passage and a backward air supply passage are provided in the main body casing. and a bushing is provided at the proximal end of the main body casing, and an air supply passage is formed in the main body casing in which the bushing and the switching valve air supply port communicate with each other via a valve switch.

〔Example〕

Next, embodiments of the present invention will be explained in detail based on the drawings.

Figure 1 is a schematic longitudinal cross-sectional view of the present invention;
The figure is a schematic vertical cross-sectional view showing the piston rod in a sliding state.

The present invention relates to a reciprocating pneumatic tool mainly adapted to file work and saw work that requires a long stroke.A piston rod 2 is installed inside a main body casing 1 so as to be able to reciprocate, and a piston 3 is fixed to the piston rod 2. At the same time, the switching valve 4
An air chamber 5 in which the piston 3 is housed and a valve chamber 6 in which the switching valve 4 is housed are formed in the main body casing 1, and the air chamber 5 A forward-acting cylinder vent 7 and a backward-acting cylinder vent 8 are provided in front and behind the piston 3, respectively, and a cylinder exhaust port 10 is connected to the exhaust passage 9 provided in the main body casing 1. A switching valve air supply port 11 is provided to the valve chamber 6, and a forward switching valve exhaust port 12 and a backward switching valve exhaust port are provided before and after the switching valve air supply port 11. A forward movement air supply passage 14 and a backward movement switching valve exhaust port 13 are formed, respectively, and communicate the forward movement switching valve exhaust port 12 and the forward movement cylinder vent to the main body casing 1. The double-acting cylinder vent 8
In addition, a bushing 16 serving as an inlet for compressed air is provided at the base end of the main body casing 1, and the bushing 16 and the switching valve air supply port 1
By forming an air supply passage 18 in the main body casing 1 that communicates with the piston rod 2 through the valve switch 17, the switching valve is operated with a time difference from the reciprocating movement of the piston rod 2 to which the piston 3 is fixed. 4
is forced to reciprocate, and the switching valve air supply port 11 and the forward switching valve exhaust port 12 or the backward switching valve exhaust port 13 are alternately placed in a ventilation state.

That is, a substantially cylindrical main body casing 1 is connected to a compressor and a hose (not shown) on the base end side, and is provided with a bushing 16 that serves as an inlet for compressed air, and is capable of reciprocating in the axial direction toward the central part. A cylinder 5a for an air chamber holds the piston rod 2 with respective sleeves 1a and 1b provided on the center side and at appropriate locations, and slidably houses the piston 3 in front and behind the sleeves 1a provided on the center side. and front and rear bulkheads 5
b forms an air chamber 5, and a switching valve cylinder 6a that slidably houses the switching valve 4 forms a valve chamber 6. A lever 1 is connected to the passage 9 and is turned on and off by pressing or releasing the head 17a of the valve switch 17 on one side of the trunk circumference at the proximal end using the lever principle.
9, the valve switch 17 is moved toward the center of the main body casing 1 by pressing the head 17a by grasping the lever 19 by hand,
By supplying compressed air from the bushing 16 to the air supply passage 18 and opening the lever 19, the coil spring 16 moves the air supply passage 18 in the outer circumferential direction, thereby blocking the air supply passage 18.

The piston rod 2 is slidably held by sleeves 1a and 1b provided on the main body casing 1, and the tip side is internally exposed from the main body casing 1, and the tip side is provided with a file, etc.
A chuck 20 for mounting a tool such as a saw is provided, and a narrow diameter portion 2b having a step portion 2a and a length on which the switching valve 4 can slide is formed on the base end side of the piston rod 2. A cylindrical switching valve 4 having a flange-like bulging part 4a formed at both ends is passed through the diameter part 2b, and a stop part 2c is provided at the base end, and the stepped part 2
a and the stop portion 2c limit the sliding range of the switching valve 4 to a fixed interval, and the switching valve 4 is connected to the piston rod 2 and the switching valve cylinder 6 of the valve chamber 6.
The disk-shaped piston 3, which is installed inside to be able to slide with the air chamber cylinder 5a of the air chamber 5, has a slight width to the circumference of the body. A sliding portion 3a is formed, which is sandwiched between a protruding ring 2d formed on the piston rod 2 and a stop ring 2e to securely fix it.

The air chamber cylinder 5a of the air chamber 5 is provided with a forward cylinder vent 7 and a backward cylinder vent 8 for supplying compressed air to the air chamber 5 before and after the piston 3 that slides back and forth, respectively. Through the reciprocating movement of the piston 3, either the forward cylinder vent 7 or the backward cylinder vent 8 is brought into communication with the valve chamber 6. , to a position intermediate between the two cylinder vents 7, 8 of the cylinder;
In other words, a cylinder exhaust port 10 is bored at a position that opens and closes when the piston 3 slides, and the cylinder exhaust port 10 communicates with an exhaust passage 9 provided in the main body casing 1 and connected to the atmosphere. It is something.

The main body casing 1 includes a forward air supply passage 14 (represented by a dotted line in the drawing) that connects the forward switching valve exhaust port 12 and the forward cylinder vent 7, the backward switching valve exhaust port 13, and the backward cylinder vent 7. The exhaust passage 9, which has an opening connected to the atmosphere at its tip, is connected to the air chamber cylinder 5a of the air chamber 5. It communicates with a cylinder exhaust port 10 bored into the cylinder, and communicates with the front and rear of the valve chamber 6 to exhaust air that is no longer needed in the valve chamber 6.

Furthermore, the present invention is constructed by forming an air supply passage 18 that communicates the bushing 16 at the proximal end of the main body casing 1 with the switching valve air supply port 11 via a valve switch 17.

[Effect]

In the present invention, first, compressed air is supplied from the bushing 16 at the base end of the main body casing 1, and the lever 1
By squeezing the switch 9 by hand, the valve switch 17 enters the ventilation state, and the compressed air passes through the supply passage and enters the switching valve cylinder 6 in the valve chamber 6.
The air flows into the valve chamber 6 from the switching valve inlet 11 drilled in the valve chamber 6, and in the case shown in FIG. 13, and is supplied to the air chamber 5 through the double-acting cylinder vent 8 via the double-acting air supply passage 15.

Next, the compressed air supplied to the air chamber 5 presses the piston 3 fixed to the piston rod 2, the piston rod 2 slides backward, and when the sliding portion 3a of the piston 3 passes through the cylinder exhaust port 10, It is discharged into the atmosphere from an exhaust passage 9 communicating with the cylinder exhaust port 10.

When the compressed air presses the piston 3, the piston rod 2 slides, and as the piston rod 2 slides, the switching valve 4 is moved slightly between the step part 2a formed in the narrow part 2b of the piston rod 2. It is forcibly slid backward by the stepped portion 2a with a time difference due to the sliding at a constant interval depending on the width, as shown in Fig. 2, and in Fig. 2,
The compressed air that has flowed into the valve chamber 6 from the switching valve air supply port 11 is supplied to the air chamber 5 by the forward cylinder vent 7 through the forward air supply passage 14 and the piston 3.
is a device that applies compressed air energy to make it slide forward, and as the piston rod 2 slides,
The switching valve 4 and the stop part 2c provided at the base end of the piston rod 2 are forcibly slid forward by the stop part 2c with a certain sliding time difference depending on the width. be.

Incidentally, the air that is no longer needed in the valve chamber 6 is discharged to the atmosphere from the connected exhaust passage 9.

[Effect of idea]

The present invention consists of the above-mentioned structure and operation, and the switching valve is forcibly reciprocated with a time difference from the reciprocating movement of the piston rod to which the piston is fixed, and the switching valve air supply port and forward switching valve exhaust port are Alternatively, by alternately venting one side of the reciprocating switching valve exhaust port, the energy of the compressed air is directly transmitted as the kinetic energy of the reciprocating motion of the piston rod, and the reciprocating air has a stable long stroke piston rod. It is an innovative and highly practical idea that can provide tools.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view of the present invention. Second
The figure is a schematic vertical cross-sectional view showing the piston rod in a sliding state. 1...Main casing, 1a, 1b...Sleeve,
2...Piston rod, 2a...Step part, 2b...Slim diameter part, 2c...Stopping part, 2d...Protruding ring, 2e...Stopping ring, 3
...Piston, 3a...Sliding part, 4...Switching valve, 4
a...Bulging part, 5...Air chamber, 5a...Air chamber cylinder, 5b...Partition wall, 6...Valve chamber, 6a...Cylinder for switching valve, 7...Forward cylinder vent, 8...Backward cylinder vent, 9...Exhaust passage, 10...Cylinder exhaust port, 11...Switching valve air supply port, 12...Forward switching valve exhaust port, 13...
Reverse acting switching valve exhaust port, 14... Forward air supply passage, 15... Reciprocating air supply passage, 16... Bushing, 17... Valve switch, 18... Air supply passage, 19... Lever, 20... Check.

Claims (1)

[Scope of utility model registration request] A piston rod is installed inside the main body casing so as to be able to reciprocate, the piston is fixed to the piston rod, and a switching valve is installed around the piston so that it can slide at regular intervals, and an air chamber in which the piston is installed and a switching valve are installed inside. valve chambers are respectively formed in the main casing, and a forward cylinder vent and a backward cylinder vent are respectively bored in the air chamber before and after the piston is sandwiched therein, and a forward cylinder vent and a backward cylinder vent are respectively provided in the main casing. A cylinder exhaust port that communicates with the exhaust passage is provided at an intermediate position between the two cylinder vents, and a switching valve air supply port is connected to the valve chamber, and a forward switching valve exhaust port and a return valve are provided before and after the switching valve air supply port. a forward movement switching valve exhaust port, and a forward movement air supply passage that connects the forward movement switching valve exhaust port and the forward movement cylinder vent to the main body casing; the backward movement switching valve exhaust port; A double-acting air supply passage is formed to communicate with the double-acting cylinder vent, and in addition, a bushing is provided at the base end of the main casing to serve as an inlet for compressed air, and the bushing and the switching valve air supply are provided. By forming an air supply passage in the main body casing that communicates with the opening via a valve switch, the switching valve is forced to reciprocate with a time difference from the reciprocating movement of the piston rod to which the piston is fixed. A reciprocating pneumatic tool characterized in that the switching valve air supply port and the forward switching valve exhaust port or the backward switching valve exhaust port are alternately brought into a ventilation state.