JP2007098559A - Pneumatic drive tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the stroke length of a tool in a pneumatic drive tool. <P>SOLUTION: This pneumatic drive tool includes: first and second pistons 18, 20 energized to approach each other by first and second energizing means 24, 26 in a housing 12. Subsequently, the compressed air is supplied between the pistons, and the pistons 18, 20 are respectively driven backward and forward. Further, the tool includes exhaust ports 20b-1 to 20b-4 for discharging the compressed air to the outside, thereby returning the pistons forward and backward by the respective energizing means. The exhaust ports 20b-1 to 20b-4 are opened to discharge the compressed air to the outside at a point of time the first and second pistons 18, 20 are driven forward and backward by a predetermined distance. In this case, the exhaust ports 20b-1 to 20b-4 are varied in set positions in the axial direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pneumatic drive tool such as a hand-held saw that is driven by compressed air.

  Various pneumatic reciprocating tools of this type have been developed. (For example, see Patent Document 1 and Patent Document 2)

In these conventional reciprocating tools, the stroke length of the driven tool is constant and cannot be adjusted.
4-2781 US Patent 5,755,292

  However, it is desired that the stroke length can be adjusted according to the object to be processed by the tool, the place where the work is performed, and the like. The present invention has been made in view of the above points, and an object of the present invention is to provide a pneumatic driving tool that can perform such adjustment without complicating the structure.

That is, the present invention
A tubular housing;
A first piston provided in the housing so as to be movable in the axial direction of the housing;
A second piston movably provided on the axially front end side of the first piston;
A tool holding member that is drivingly connected to the second piston, extends forward in the axial direction, and holds the tool;
First urging means for urging the first piston forward;
Second urging means for urging the second piston backward;
Compressed air is supplied between the first and second pistons, and the compressed air drives the first and second pistons backward and forward against the first and second urging means, respectively. Compressed air supply passage
When the space between the first and second pistons is expanded in the axial direction by the compressed air, the compressed air is communicated with the space to discharge the compressed air from the space to the outside. An exhaust port for returning the second piston to the front and rear by the first and second urging means, respectively, when the first and second pistons are driven a predetermined distance rearward and forward And an exhaust port that is opened to exhaust the compressed air to the outside,
Have
The drive distance of the first and second pistons driven by the compressed air can be adjusted by adjusting the position of the exhaust port in the axial direction when the compressed air is discharged when the air is released. A pneumatic drive tool is provided.

  That is, in this pneumatic drive tool, the driving distance of the first and second pistons is adjusted by adjusting the position of the exhaust port in the axial direction when the compressed air is discharged from the space between the first and second pistons. Can be adjusted.

In particular,
One of the first and second pistons has a cylindrical portion extending in the axial direction;
A plurality of the exhaust ports are provided at predetermined intervals along the axial direction in the cylindrical portion,
The cylindrical portion engages with the other outer peripheral surface of the first and second pistons so as to be slidable in the axial direction,
In a state where compressed air is not supplied to the first and second pistons, the exhaust port is closed by the other outer peripheral surface,
An exhaust port closing surface that is slidably engaged with the one outer peripheral surface of the first and second pistons, and when the compressed air is not supplied to the first and second pistons, the closing surface is An exhaust port closing member that is spaced apart from the exhaust port in the axial direction and is set to a position such that the exhaust port moves toward the exhaust port closing surface as the first and second pistons are driven by compressed air. An exhaust port closing member capable of adjusting a setting position in the axial direction;
When the first and second pistons are driven rearward and forward by compressed air and the outer peripheral surface of the other piston changes the required number of exhaust ports from the closed state to the open state, the exhaust port closing member Compressed air is allowed to be exhausted outside through an exhaust port that is not closed,
Adjusting the driving distance of the first and second pistons by determining the required number when the compressed air is allowed to be discharged to the outside according to the set position of the exhaust port closing member. Can

More specifically,
A cylindrical adjustment member that is screw-engaged with the outer peripheral surface of the housing and is displaced in the axial direction on the housing by being screwed. An annular groove is formed on the inner peripheral surface. An adjusting member,
An adjustment hole provided to radially penetrate the housing along the axial direction;
A pin fixed to the exhaust port closing member and extending in a radial direction through the adjustment hole and slidably engaged with the annular groove, and by rotating the adjustment member, the axis of the exhaust port closing member The setting position in the direction can be adjusted.

In another embodiment,
A cylindrical adjustment member that is screw-engaged with the outer peripheral surface of the housing and is displaced in the axial direction on the housing by being screwed, and includes a pin protruding radially from the inner peripheral surface An adjustment member having,
An adjustment hole formed to radially penetrate the housing to allow movement of the pin when the adjustment member is screwed on the housing;
An annular groove formed in the exhaust port closing member and slidably engaged with the pin that has passed through the adjustment hole, and by screwing the adjustment member, The set position of the exhaust port closing member in the axial direction is adjusted.

In yet another example,
A cylindrical member that is slidable on the outer peripheral surfaces of the first and second pistons and that is adjustable in position in the axial direction, and is provided so that the exhaust port penetrates in the radial direction. Having a tubular member,
The exhaust port is closed by one outer peripheral surface of the first and second pistons when compressed air is not supplied between the first and second pistons.

  In this case, the driving distance of the first and second pistons can be adjusted by adjusting the position of the cylindrical member in the axial direction.

  According to the present invention, the driving distance of the first and second pistons driven by compressed air can be adjusted according to the work object, the work place, etc., and therefore more appropriate work can be performed. It becomes.

  An embodiment of a pneumatic drive reciprocating tool when the present invention is applied to a saw will be described in detail with reference to the accompanying drawings.

  1 to 3 and FIGS. 4 and 5 show two examples in which the setting of the reciprocating stroke length is changed in the pneumatic drive reciprocating tool 10.

  The reciprocating tool 10 includes a cylindrical housing 12, a fixed shaft 14 that extends forward in the axial direction of the housing from the rear end of the housing, and a cylindrical first shaft that is slidable along the fixed shaft 14. 1 piston 18, a second piston 20 provided on the front end side of the first piston, and connected to the second piston 20, extending through the front end of the housing 12 in the axial direction, and a tool ( And a tool holding member 22 that holds a tool holding member (not shown).

  The first piston 18 is biased forward by first biasing means (coil spring) 24, and the second piston 20 is biased rearward by second biasing means (coil spring) 26. In the state where the compressed air shown in FIGS. 1 and 4 is not introduced, the first and second pistons 18 and 20 are brought closer to each other by the first and second urging means 24 and 26.

  The fixed shaft 14 is fixed to a rear end member 28 that closes the rear end of the housing 12. The fixed shaft 14 extends through the rear end member 28 and is compressed from a compressed air introduction passage 30 that communicates with a compressor (not shown). A compressed air supply path 32 that receives air and supplies the air between the first and second pistons 18 and 20 is provided. In the compressed air supply path 32, a closed position (FIGS. 3 and 5) for closing the compressed air supply path 32, and an open position for opening the compressed air supply path 32 on the rear end side of the housing from the closed position. (FIGS. 1 and 4) is provided with a ball-shaped valve body 34 that can be displaced between the valve body 34 and the valve body 34 is urged to a closed position by a compression spring 36 provided in the compressed air supply path 32. Has been. On the other hand, the tool holding member 22 fixed to the second piston 20 has a rear end aligned with the compressed air supply path 32 and protrudes rearward from the second piston 20, and the first and second pistons. A valve opening / closing operation unit 38 that operates opening / closing of the valve body 34 in accordance with the movements of 18 and 20 is provided.

  The second piston 20 has a cylindrical wall 20a extending rearward, and the first piston 18 is inserted into the cylindrical wall 20a so as to be slidable. The cylindrical wall 20a is provided with first to fourth exhaust ports 20b-1 to 20b-4 penetrating in the diametrical direction so as to be spaced apart from each other in the axial direction. When compressed air is supplied between the first and second pistons 18 and 20 through the compressed air supply path 32, the first and second pistons 18 and 20 are respectively connected to the first and second urging means. Although it is driven backward and forward against 24 and 26 (FIG. 2), the first exhaust port 20b-1 to the second, third, and fourth exhaust ports 20b-2 to 20b- as the driving proceeds. 4 is communicated with the space between the first and second pistons 18 and 20 in order (FIGS. 3 and 5).

  A cylindrical exhaust port closing member 44 is provided between the inner peripheral surface of the housing 12 and the outer peripheral surface of the second piston 20, and can be displaced in the axial direction of the housing 12. A connecting pin 50 is fixed to the exhaust port closing member 44, and the connecting pin 50 passes through a through long hole 46 formed in the housing 12 so as to extend in the axial direction of the housing 12. It is slidably engaged with an annular groove 53 of a cylindrical adjustment member 52 mounted on the top. The adjustment sleeve 52 is screw-engaged on the outer peripheral surface of the housing 12 and is screwed on the housing 12 to displace the exhaust port closing member 44 in the axial direction of the housing 12 via the connecting pin 50. Adjustable. Specifically, in FIG. 1, the exhaust port closing member 44 is set so that the connecting pin 50 is positioned at the left end of the through long hole 46. In FIG. 4, the connecting pin 50 is on the right side of FIG. The exhaust port closing member 44 is set so as to be at a higher position.

  That is, at the two set positions, the relative positions of the exhaust port closing member 44 with respect to the first and second pistons 18 and 20 are different. In other words, the outer periphery of the second piston 20 of the exhaust port closing member 44 is different. The axial position of the exhaust port closing surface 45 that is in sliding engagement with the surface with respect to the exhaust ports 20b-1 to 20b-4 is different. Such adjustment of the position of the exhaust port closing member 44 causes the following differences in the operation of the reciprocating tool 10.

  As described above, when compressed air is introduced into the reciprocating tool 10 in the state of FIGS. 1 and 4, the first and second pistons 18 and 20 move away from each other, and as the movement proceeds. The first exhaust port 20b-1 communicates with the second, third, and fourth exhaust ports 20b-2 to 20b-4 in order to communicate with the space between the first and second pistons 18 and 20. On the other hand, when the second piston 20 is driven forward by a predetermined distance or more, the exhaust port closing member 44 is sequentially moved from the first exhaust port 20b-1 to the second, third, and fourth exhaust ports 20b-2 to 20b-4. It comes to close.

  On the other hand, when the exhaust port closing member 44 is set to the leftmost position as shown in FIG. 1, the first exhaust port 20 b-1 is closed by the closing surface 45 of the exhaust port closing member 44. The distance traveled forward (leftward) of the second piston 20 is longer than when the exhaust port closing member 44 is set on the right side of the position shown in FIG. For this reason, in the example shown in FIG. 1, when the first and second pistons 18 and 20 are driven by introduction of compressed air, the first exhaust port 20 b-1 is closed by the closing surface 45 of the exhaust port closing member 44. Before being performed, the closed state of the first exhaust port 20b-1 by the outer peripheral surface of the first piston 18 becomes an open state. Therefore, at this time, the compressed air supplied between the first and second pistons 18 and 20 is opened. Is exhausted to the outside. At almost the same time, the valve body 34 is in the closed position.

  Therefore, in the example shown in FIG. 1, the driving of the first and second pistons 18 and 20 ends when the first exhaust port 20 b-1 is opened (FIG. 3), and the first and second pistons 18. , 20 are returned to the state of FIG. 1 by the first and second urging means 24, 26.

  On the other hand, in the example shown in FIG. 4, the exhaust port closing member 44 is set to the right than in the case of FIG. 1, so that when the first exhaust port 20 b-1 is opened by the first piston 18. Then, the exhaust port closing member 44 is closed (not shown), and further, the drive by the compressed air proceeds (relative displacement speeds of the first and second pistons 18 and 20, and accordingly, the exhaust ports 20b-1 to 20b-1). The relative displacement speed of the first piston with respect to 20b-4 is twice the relative displacement speed of the first piston 20 with respect to the exhaust port closing member 44), so that the third exhaust port 20b-3 with the exhaust port closing member 44 is provided. The fourth exhaust port 20b-4 is opened at the time when the closing is performed (FIG. 5), and at that time, the valve body 34 is set to the closing position. That is, in the setting conditions of FIG. 4, the driving distance to the front of the second piston 20 is larger than in the case of FIG. 1 (the number of the sum of the length of the exhaust port and the length between the exhaust port and the exhaust port) Therefore, the stroke length of the tool connected to the second piston 20 is also increased.

  The compressed air exhausted from the exhaust port is exhausted to the outside of the housing through the internal space 40 between the housing 12 and the fixed shaft 14 and the exhaust passage 42 formed in the rear end member 28. Yes.

  FIG. 6 shows another embodiment of a pneumatic drive tool. The configuration of this tool is basically the same as that of the above-described embodiment, and components having the same functions are denoted by the same reference numerals. In this tool, a cylindrical member 60 having an inner peripheral surface that slides with the outer peripheral surfaces of the first and second pistons is set to be adjustable in an axial position, and one exhaust port 62 is provided in the cylindrical member 60. If the exhaust port 62 is provided and is not driven by compressed air, the exhaust port 62 is closed by the outer peripheral surface of one of the first and second pistons 18 and 20 (the first piston in the illustrated example) and compressed. When the first and second pistons 18 and 20 are driven by a predetermined length by air, the exhaust port 62 is opened and the compressed air is exhausted.

  Also in this embodiment, the driving distance of the first and second pistons can be adjusted by adjusting the position of the cylindrical member 60 in the axial direction.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the present invention defined in the claims. For example, the pin 50 is fixed to the exhaust port closing member 44. However, the pin is fixed to the adjustment member 52 so as to extend in the radial direction, and the radially inner end thereof is connected to the exhaust port closing member. The position of the exhaust port closing member in the axial direction can be adjusted by rotating the adjustment member 52 so as to be slidably engaged with the annular groove provided in the shaft 44. Moreover, although the example which provided the cylindrical part which provided the exhaust port in the 2nd piston 20 was shown, this cylindrical part can be provided in the 1st piston 18. FIG.

It is a longitudinal cross-sectional view of the pneumatic reciprocating tool which concerns on this invention, and is a figure which shows the 1st setting state when the drive by compressed air is not performed. It is a longitudinal cross-sectional view of the tool of FIG. 1, and the state by which the drive by compressed air was started is shown. It is a longitudinal cross-sectional view of the tool of FIG. 1, and the state where supply of compressed air is complete | finished and this compressed air is exhausted is shown. It is a figure which shows the 2nd setting state when the drive by compressed air is not performed in the same tool as FIG. It is a longitudinal cross-sectional view of the tool in the setting state of FIG. 4, and shows the state where supply of compressed air is completed and the compressed air is exhausted. It is a longitudinal section showing other embodiments of a pneumatic drive tool concerning the present invention.

Explanation of symbols

Pneumatic drive reciprocating tool 10
Housing 12
Fixed shaft 14
First piston 18
Second piston 20
Cylindrical wall 20a
1st thru | or 4th exhaust port 20b-1-20b-4
Tool holding member 22
First biasing means (coil spring) 24
Second urging means (coil spring) 26
Rear end member 28
Compressed air introduction path 30
Compressed air supply path 32
Disc 34
Compression spring 36
Valve opening / closing operation section 38
Housing internal space 40
Exhaust passage 42
Exhaust port closing member 44
Exhaust port closing surface 45
Through long hole (adjustment hole) 46
Connecting pin (pin) 50
Adjustment sleeve (adjustment member) 52
Annular groove 53
Cylindrical member 60
Exhaust port 62

Claims (5)

A tubular housing;
A first piston provided in the housing so as to be movable in the axial direction of the housing;
A second piston movably provided on the axially front end side of the first piston;
A tool holding member that is drivingly connected to the second piston, extends forward in the axial direction, and holds the tool;
First urging means for urging the first piston forward;
Second urging means for urging the second piston backward;
Compressed air is supplied between the first and second pistons, and the compressed air drives the first and second pistons backward and forward against the first and second urging means, respectively. Compressed air supply passage
The compressed air supplied between the first and second pistons is discharged to the outside so that the first and second pistons are returned to the front and rear by the first and second urging means, respectively. An exhaust port that is opened to exhaust the compressed air to the outside when the first and second pistons are driven rearward and forward by a predetermined distance;
Have
The drive distance of the first and second pistons driven by the compressed air can be adjusted by adjusting the position of the exhaust port in the axial direction when the compressed air is discharged when the air is released. Pneumatic drive tool. One of the first and second pistons has a cylindrical portion extending in the axial direction;
A plurality of the exhaust ports are provided at predetermined intervals along the axial direction in the cylindrical portion,
The cylindrical portion engages with the other outer peripheral surface of the first and second pistons so as to be slidable in the axial direction,
In a state where compressed air is not supplied to the first and second pistons, all of the exhaust ports are closed by the other outer peripheral surface,
An exhaust port closing surface that is slidably engaged with the one outer peripheral surface of the first and second pistons, and when the compressed air is not supplied to the first and second pistons, the closing surface is An exhaust port closing member that is spaced apart from the exhaust port in the axial direction and is set to a position such that the exhaust port moves toward the exhaust port closing surface as the first and second pistons are driven by compressed air. An exhaust port closing member capable of adjusting a setting position in the axial direction;
When the first and second pistons are driven rearward and forward by compressed air, respectively, and the outer peripheral surface of the other piston changes the required number of exhaust ports from the closed state to the open state, the exhaust port closing member Compressed air is allowed to be exhausted outside through an exhaust port that is not closed,
2. The pneumatic drive tool according to claim 1, wherein the required number when compressed air is allowed to be discharged to the outside is determined by the set position of the exhaust port closing member. 3. A cylindrical adjustment member that is screw-engaged with the outer peripheral surface of the housing and is displaced in the axial direction on the housing by being screwed. An annular groove is formed on the inner peripheral surface. An adjusting member,
An adjustment hole provided along the axial direction and extending radially through the housing;
A pin fixed to the exhaust port closing member and extending radially through the adjustment hole and slidably engaged with the annular groove, and by screwing the adjustment member, through the pin, the pin The pneumatic drive device according to claim 2, wherein a setting position of the exhaust port closing member in the axial direction can be adjusted. A cylindrical adjustment member that is screw-engaged with the outer peripheral surface of the housing and is displaced in the axial direction on the housing by being screwed. The pin projects radially from the inner peripheral surface. An adjustment member having
An adjustment hole formed to radially penetrate the housing to allow movement of the pin when the adjustment member is screwed on the housing;
An annular groove formed in the exhaust port closing member and slidably engaged with the pin that has passed through the adjustment hole, and by screwing the adjustment member, The pneumatic drive device according to claim 2, wherein a setting position of the exhaust port closing member in the axial direction can be adjusted. A cylindrical member that is slidable on the outer peripheral surfaces of the first and second pistons and that is adjustable in position in the axial direction, and is provided so that the exhaust port penetrates in the radial direction. Having a tubular member,
The exhaust port is configured to be closed by one outer peripheral surface of the first and second pistons when compressed air is not supplied between the first and second pistons. Item 2. The pneumatic drive device according to Item 1.

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