JPH0616671Y2 - Safety device for nailer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a safety device in a nailing machine that prevents malfunction by a contact valve that interlocks with a pressing operation of a contact member against a material to be driven.

(Prior art and its problems) In a nailing machine that impacts a striking piston with compressed air or the like to strike a nail, in a nail lever, which is arranged near a grip formed in a housing, There is provided a safety device that activates the nail driving machine only when the contact operation with the material to be driven by the contact member arranged near the tip of the injection nose portion is performed at the same time.

The usual safety device is that the upper end of the contact member protruding from the tip of the nose part is extended to the vicinity of the trigger lever via the contact arm, and the trigger valve for starting is activated by the upward movement of the contact arm and the operation of the trigger lever. Is configured to operate.

When the contact arm at the upper end of the contact member is extended to the trigger lever in this way, it is necessary to form a sliding guide for the contact arm and to secure a space for disposing the contact arm. It makes the structure of the complicated and causes a trouble in driving,
It may cause a failure. Further, it is necessary to lengthen the operation stroke of the contact arm, which deteriorates the operation characteristics of the nail driver.

On the other hand, as another technique, there is known a safety device that activates a contact valve directly connected to a trigger valve for activation by operating a contact member and activates a nailing machine by operating both valves (US Patent Third, 28
8, 339).

In the above safety device, the contact valve is connected to the control chamber of the main valve and the exhaust passage of the trigger valve, and when the contact valve and the trigger valve are simultaneously operated, the control chamber of the main valve is connected to the atmosphere and the main valve is connected. Is to operate.

However, in the above mechanism, the stem of the contact valve is provided with two sliding seals separated in the sliding direction,
Since the flow path is switched by the seal crossing the opening formed in the wall of the valve housing, a large operating stroke is required and the operability of the nail driver is not improved.

Also, if a face seal structure is adopted as the valve mechanism, the valve stem is not affected by compressed air pressure at the time of operating the contact member for the first time, and the operating force against the restoring spring force acting on the contact member is applied. On the other hand, when the trigger valve is operated first, compressed air acts on the sealing surface of the valve stem of the contact valve via the trigger valve, and the compressed air pressure presses the upper end of the contact valve. However, there is a problem that the force required to operate the contact member is increased.

(Object of the Invention) The present invention can simplify the mechanism around the nose part of the nailing machine and greatly changes the operating load of the contact member regardless of whether the trigger lever or the contact member is operated first. To provide a stabilizer for a nailing machine that does not allow it.

(Means for Solving the Problem) As a means for solving the above problems, a safety device in a nailing machine according to the present invention is provided with a nose portion for ejecting nails at a lower end side and a grip portion for gripping. A housing formed integrally, and arranged in the housing,
A movable cylinder that slidably accommodates a striking piston integrally formed with a driver for nail striking that can slide in the injection port of the nose part, and is actuated by the air pressure in the control chamber and compresses the movable cylinder. In a nailing machine equipped with an air chamber and a main valve selectively connected to the atmosphere, a starting valve for supplying and exhausting compressed air in a control chamber of the main valve is provided near the grip by operating a trigger lever. An exhaust member that is operably disposed, has a contact member that is operated by contact with a material to be driven at the tip of the nose portion, and that is operated by operating the contact member and that is in communication with an exhaust passage of the start valve. A contact valve that connects and disconnects the space for use with the atmosphere is provided, and a face seal that maintains a normally isolated state with the atmosphere is provided at one end. An exhaust gas formed between both seals, in which a valve stem having a sliding seal having an outer diameter substantially the same as the outer diameter of the seal separated from the face seal on the other end side is slidably arranged in the valve housing. The space for communication is communicated with the exhaust passage of the starting valve.

(Operation and effect of device) According to the above configuration, since the outer diameters of the face seal and the sliding seal of the contact valve are substantially the same, regardless of whether there is compressed air in the exhaust space, that is, The operation load for operating the contact valve by the contact member is substantially constant regardless of whether the contact member is pressed against or the trigger lever is pulled first.

In addition, since the seal on the side that connects to and disconnects from the atmosphere has a face seal configuration, the face seal of the valve stem simply abuts and separates from the annular projection wall of the valve chamber to perform sealing and release. As a result, the switching stroke is small, and quick operation is possible.

Further, since only the contact member and the contact valve are provided around the nose portion and the conventional contact arm can be omitted, the mechanism around the nose portion can be simplified.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a recoilless compressed air actuated nailing machine. The nailing machine includes a housing 1 having a compressed air chamber a connected to a compressed air supply source, and a grip 2, respectively. A nose portion 4 having an ejection port for a nail 3 is provided on the lower end side of the housing 1, a nail supply magazine 5 is provided between the nose portion 4 and the grip 2, and the housing 1 is further provided.
A movable cylinder 6 that slides in the axial direction of the nose portion 4 is provided in the interior of the container, and the upper end of the movable cylinder 6 is closed by an upper wall 7, and a driver 8 that slides in the injection port is provided therein. Is provided slidably, and a main valve 10 selectively connects the upper wall 7 of the movable cylinder 6 and the impact piston 9 to the compressed air chamber a and the atmosphere. And drives the striking piston 9.

The housing 1 is doubly formed by an outer shell 1a and a fixed sleeve 1b provided therein, and the movable cylinder 6 is housed inside the fixed sleeve 1b. The movable cylinder 6 is slidably held in the fixed sleeve 1b arranged in the housing 1 so as to be separated from the compressed air chamber a. On the peripheral wall of the fixed sleeve 1b, the supply / exhaust port 1 formed on the peripheral wall near the upper end of the movable cylinder 6 is provided.
3 is formed with an opening 14 that is in constant communication with the fixed sleeve 1b, and an annular main valve control chamber 12 that slidably accommodates the main valve 10 is formed on the outer peripheral side of the fixed sleeve 1b. Is provided with a sleeve-shaped main valve 10 which is slidable with respect to the fixed sleeve 1b. The main valve 10 has an exhaust position (the position shown in FIG. 1) for connecting a supply / exhaust port 13 formed in the upper part of the movable cylinder 6 from an opening formed in the upper part of the fixed sleeve 1b to an exhaust port 15 at the upper end of the housing 1. ) And the air supply position (the position shown in FIG. 2) that connects the supply / exhaust port 13 from the opening 14 to the compressed air chamber a.

Next, the main valve 10 is constantly urged to the exhaust position side by the spring 16 and moves to the exhaust position and the air supply position by supplying and discharging compressed air into the control chamber 12. Drive control of the main valve 10 is performed. Is performed by a pilot valve 18 provided between the housing 1 and the grip 2. Due to the vertical movement of the valve stem 19, the pilot valve 18 connects the inside of the main valve control chamber 12 to the compressed air chamber a when it is in the upper position (the position shown in FIG. 1) and moves it to the lower position (see FIG. 2). When it is in the position shown in (1), the main valve 10 is driven by connecting to the atmosphere.

By the way, the vertical movement of the pilot valve stem 19 is configured to interlock with the starting valve 22 that is manually operated by the trigger lever 21. That is, the pilot valve stem 19 is formed hollow and the lower end portion thereof is inserted into the start valve chamber 23. The upper part of the starting valve stem 24 enters the inside of the pilot valve stem 19 and is urged downward by the spring 25, and the lower end is engaged with the trigger lever 21. The starting valve stem 24 always has the compressed air chamber a as shown in FIG. 1 and an opening 26 formed in the side wall of the pilot valve stem 19.
Is connected to a gap (control space) 27 between the start valve chamber 23 and the lower end of the pilot valve stem 19 and is biased to a position for operating the pilot valve stem 19 to the upper position.

The operation of the trigger lever pushes up the starting valve stem 24 as shown in FIG. 2, whereby the seal ring 28 exposes the lower end of the valve stem 19 of the pilot valve 18 to the control space 27 not shown. The exhaust port 41 communicating with is communicated. The contact valve connects the exhaust port 41 to the atmosphere by pressing it against the nose portion 4 and the material to be driven. As a result, the control space 27 of the pilot valve communicates with the atmosphere, and the pressure in the control space 27 decreases. The control space 27 is always in communication with the compressed air chamber a through the opening 26, but since the amount of exhaust air is set to be larger than the amount of inflow air from the opening, the pressure in the control space 27 is It descends. As a result, the pilot valve stem 19 is pushed down by the compressed air in the compressed air chamber a.

With the above configuration, when the trigger lever 21 is not operated, as shown in FIG. 1, the starting valve stem 24 is positioned downward by the force of the spring 25, and the pilot valve stem 19 is pushed up by compressed air to an upper position. Therefore, compressed air is supplied into the main valve control chamber 12,
This air pressure urges the main valve 10 to the exhaust position. At this time, the striking piston 9 does not move. Next, when the trigger lever 21 is pulled, the start valve stem 24 is pushed up, while the pilot valve stem 19 is pushed down, as shown in FIG.
0 moves to the air supply position (upward) when the compressed air in the compressed air chamber a acts on the lower end of the valve when the air pressure in the control chamber 12 decreases. Therefore, the supply / exhaust port 1
Compressed air is introduced from 3 between the upper wall 7 of the movable cylinder 6 and the striking piston 9, and the striking piston 9 is driven to drive out the nails supplied into the nose portion 4. Then, when the trigger lever 21 is released, the main valve 10 moves again from the air supply position in FIG. 2 to the exhaust position in FIG. 1, and the compressed air in the movable cylinder 6 is supplied from the air supply / exhaust port 13 to the opening portion 14, Exhausted through the exhaust port 15, the striking piston 9 rises and returns by the compressed air accumulated in the blowback chamber 29 at the time of striking.

Next, when the striking piston 9 is driven to strike downward, the force due to the reaction acts on the upper wall 7 of the movable cylinder 6, so that the movable cylinder 6 moves upward, and as a result, the reaction due to the driving of the striking piston 9 occurs. Will be canceled.

The upward return movement of the movable cylinder 6 is performed by compressed air to the cylinder return chamber 31 formed between the diameter difference portion 30 formed on the outer circumference of the movable cylinder 6 and the inner circumference of the housing 1 by a valve (not shown). It is carried out by feeding and discharging. When the compressed air is supplied into the cylinder return chamber 31, the movable cylinder 6 is driven downward by the air pressure based on the diameter difference. Therefore, the striking piston 9
It can be returned after it has risen due to the reaction when driving.

Next, as shown in FIGS. 3 (a) and 3 (b), a contact member 11 which is operated by contact with the driven material 42 is arranged at the tip of the nose portion 4, and in the vicinity of the contact member 11. A contact valve 45 is provided.

An adjuster 46 is screwed onto the upper part of the contact member 11, and a push rod 47 is mounted on the upper part of the adjuster 46.
Are formed. The contact member 11 is urged by a spring 58 so that the push rod 47 is separated from the contact valve 45 and the tip of the contact member 11 projects beyond the nose portion 4.

The contact valve 45 has a valve chamber 48 whose lower part is opened.
The valve stem 49 is slidably accommodated in the inside of the valve. The lower end of the valve stem 49 is arranged to face the upper end of the push rod 47, and a constant gap 52 is formed between both ends. .

A face seal 50 is provided on the lower end side of the valve stem, and is separated from the face seal 50 on the upper end side of the valve stem 50.
There is provided a sliding seal 51 having an outer diameter substantially the same as the outer diameter. The face seal 50 is arranged so as to be able to come into contact with and separate from the upper surface of an annular projecting wall 53 formed in the lower portion of the inner wall of the valve chamber 48, and the slide seal 51 is arranged so as to be slidable on the upper portion of the inner wall of the valve chamber 48. There is. An exhaust space 55 communicating with an exhaust passage 54 communicating with the control space 27 of the starting valve 22 is formed between the face seal 50 and the sliding seal 51. Further, the upper wall of the valve chamber 48 and the valve stem 49
A spring 56 is disposed between the upper surface of the surface seal 5 and the valve stem 49, and the valve 56 is constantly urged downward by the spring 56.
0 comes into contact with the upper surface of the annular protruding wall 53, and the exhaust space 5
5 is blocked from the atmosphere.

With the above-mentioned configuration, the contact member 11 is driven into the driven material 4
Even if the activation valve 22 is operated by operating the trigger lever 21 without touching the surface of 2, the exhaust space 55 of the contact valve 45 remains blocked from the atmosphere by the surface seal 50 of the valve stem 49. Therefore, the compressed air in the control space 27 is not exhausted. afterwards,
The contact member 11 is pressed against the driven member 42 to move it relative to the housing 1, and the valve stem 49 is pressed against the spring 58 by the push rod 47, so that the first time as shown in FIG. The seal of the face space 50 of the exhaust space 55 is released, and the exhaust space 55 and the exhaust passage 54 communicating with the control space 27 are electrically connected to the atmosphere.

On the other hand, first, the contact member 11 is pressed against the driven material 42 and the valve stem 49 is pressed by the push rod 47, so that the exhaust space 55 is communicated with the atmosphere, and then the trigger lever 21 is pulled. As a result, the compressed air in the control space 27 of the start valve 22 is exhausted to the atmosphere through the exhaust space 55, so that the start valve 22 operates.

That is, the starting valve 22 has a starting valve stem 24 which is operated by manual operation of the trigger lever 21, and when the starting valve stem 24 is operated, the control space 27 at the lower end of the pilot valve stem 19 is transferred to the contact valve 45. It connects to the communicating exhaust passage 54. On the other hand, when the contact valve 45 is operated, the passage 54 communicates with the atmosphere and the control space 27 communicates with the atmosphere. Only when both the starting valve 22 and the contact valve 45 are operated, the compressed air pressure in the control space 27 is reduced and the pilot valve 18 is operated. Therefore, it is possible to prevent an explosion accident due to an erroneous operation of one of the two valves.

As described above, since the outer diameters of the face seal 50 and the sliding seal 51 of the stem of the contact valve 45 are substantially the same, regardless of whether compressed air is present in the exhaust space 55, that is, first. Regardless of whether the contact member 11 is pressed or the trigger lever 21 is first pulled, the operation load for operating the contact valve 45 by the contact member 11 is substantially constant.

Further, since the seal on the side that connects to and disconnects from the atmosphere has a face seal configuration, the face seal 50 of the valve stem 49 only contacts and separates from the annular protruding wall 53 of the valve chamber 48, and the seal and its Since the release is performed, the switching stroke is small, and quick operation is possible.

Further, since the contact member 11 and the contact valve 45 are only provided around the nose portion 4, and the conventional contact arm can be omitted, the mechanism around the nose portion can be simplified. .

[Brief description of drawings]

FIGS. 1 and 2 are explanatory views of the operation mode of the nail driver according to the present invention, and FIGS. 3 (a) and 3 (b) are operation mode explanatory views of the safety device of the nail driver. Reference numeral 1 ... Housing, 2 ... Grip portion, 4 ... Nose portion, 9 ... Impact piston, 10 ... Main valve, 1
1 ... contact member, 22 ... starting valve, 21 ...
Trigger lever, 22 …… starting valve, 45 …… contact valve, 50 …… face seal, 51 …… sliding seal, 5
5 ... Exhaust space

Claims (1)

[Scope of utility model registration request] 1. A housing in which a nose portion for injecting a nail is provided on the lower end side and a grip portion for grasping is integrally formed, and the housing is arranged in the housing and slidable in an injection port of the nose portion. A movable cylinder that slidably accommodates a striking piston integrally formed with a nail striking driver, and is operated by the air pressure in the control chamber,
In a nailing machine equipped with a main valve that selectively connects a movable cylinder inside to a compressed air chamber and the atmosphere, a starting valve for supplying and exhausting compressed air in a control chamber of the main valve is provided near the grip. A trigger member is arranged so as to be operable, and a contact member that is operated by contact with a material to be driven is arranged at the tip of the nose portion. The contact member is operated by operating the contact member, and the exhaust of the start valve is also performed. A contact valve that connects and disconnects the exhaust space that communicates with the passage with the atmosphere is provided, a face seal that maintains a normally disconnected state with the atmosphere is provided at one end, and the face seal is separated from the other end. A valve stem provided with a sliding seal having an outer diameter substantially the same as the outer diameter of the seal is slidably arranged in the valve housing, and is formed between both seals. A safety device in a nailing machine, wherein an exhaust space is communicated with an exhaust passage of the start valve.