JP5023816B2 - Driving tool - Google Patents

Description

  The present invention includes a striking mechanism including a striking cylinder provided in a tool body, a striking piston slidably accommodated in the striking cylinder, and a driver integrally coupled to the striking piston. The present invention relates to a driving tool for cooling a bumper arranged at the bottom of a cylinder.

  In general, a driving tool such as a nailing machine or a screw driving machine is provided with a striking mechanism in which a striking piston is accommodated in a striking cylinder and a driver is integrally coupled to the striking piston. A shock-absorbing cylindrical bumper is disposed at the bottom of the striking cylinder to receive the lower surface of the striking piston when it is driven.

  As the fastener is driven repeatedly, the bumper is also heated by the impact of the striking piston. Since the bumper is made of rubber, its life is shortened if it is deformed or generates heat due to repeated impacts. For this reason, it is necessary to cool a bumper.

  As a conventional bumper cooling method, a method in which compressed air is directly applied to the bumper to cool, or a method in which the exhaust passage and the outer peripheral surface of the impact cylinder are brought into contact with each other and the compressed air exhausted is used for cooling is known. ing.

JP 2003-236768 A JP 2002-321168 A Japanese Utility Model Publication No. 55-93476 Japanese Utility Model Publication No. 55-93477

  However, an effective cooling effect cannot be obtained with the conventional cooling method.

  As a result of the study of the reason by the present inventors, the heating point when the striking piston collides was not outside the bumper, but the temperature rise was greater at the lower part of the inner peripheral surface of the bumper and its vicinity. . However, in the past, only the outer surface of the bumper was cooled.

  For this reason, the following problems have not been solved. (1) Since the deformation and turning due to heat generation occur at an early stage, the life of the bumper is short. (2) To extend the service life, the outer diameter of the bumper must be increased, and the entire tool becomes larger.

  The object of the present invention is to provide a cooling device for a bumper in a driving tool that eliminates the above-mentioned drawbacks, extends the life of the bumper effectively by cooling the bumper, and does not require an increase in the outer diameter of the bumper. And

In order to solve the above-mentioned problem, the invention according to claim 1 includes a striking cylinder provided in the tool body, a striking piston slidably accommodated in the striking cylinder, and a driver integrally coupled to the striking piston. A striking mechanism configured, driving the striking piston with compressed air supplied from above the striking cylinder, striking and striking a fastener with the driver, and when the striking piston is driven, Compressed compressed air is supplied to a blowback chamber provided outside the lower portion of the impact cylinder, and after the completion of the impact, the impact piston is returned upward by the compressed air in the blowback chamber, and the compressed air In the driving tool for exhausting the air from the exhaust chamber to the outside, it is arranged at the lower part of the hitting cylinder Is provided an air supply means for sending cooling air to the inside bottom or near the hollow bumper which receives the lower surface of the striking piston, the air supply means, connecting the bottom of the blowback chamber and the striking cylinder The connection path is configured to open to the inside of the bumper, and an air storage chamber capable of temporarily storing cooling air is formed in the middle of the connection path .

The invention according to claim 2 is characterized in that, in claim 1 , a check valve is provided in a midway portion of the connecting path.

The invention according to claim 3 includes a striking mechanism constituted by a striking cylinder provided in the tool main body, a striking piston slidably accommodated in the striking cylinder, and a driver integrally coupled to the striking piston. The compressed air supplied from above the impact cylinder drives the impact piston and strikes and drives the fastener by the driver, and the compressed air compressed in the impact cylinder is driven when the impact piston is driven. The blow piston is supplied to a blowback chamber provided outside the lower portion of the impact cylinder, and after the completion of the impact, the impact piston is returned upward by the compressed air in the blowback chamber, and the compressed air is exhausted from the exhaust chamber to the outside. In the driving tool to be disposed, the hammering piston is disposed at a lower portion of the hammering cylinder. An air supply means for sending cooling air to the inside lower part of the hollow bumper receiving the surface or the vicinity thereof is provided, and the air supply means is made hollow inside the driver and has its upper end opened, and the bottom dead center of the driver. A communication hole is formed in a wall portion corresponding to the inside of the bumper at a position.

The invention according to claim 4 includes a striking mechanism comprising a striking cylinder provided in the tool body, a striking piston slidably accommodated in the striking cylinder, and a driver integrally coupled to the striking piston. The compressed air supplied from above the impact cylinder drives the impact piston and strikes and drives the fastener by the driver, and the compressed air compressed in the impact cylinder is driven when the impact piston is driven. The blow piston is supplied to a blowback chamber provided outside the lower portion of the impact cylinder, and after the completion of the impact, the impact piston is returned upward by the compressed air in the blowback chamber, and the compressed air is exhausted from the exhaust chamber to the outside. In the driving tool to be disposed, the hammering piston is disposed at a lower portion of the hammering cylinder. An air supply means for sending cooling air is provided at or near the inside lower part of the hollow bumper that receives the surface, and the air supply means is constituted by a connection path that connects the compressed air supply source and the bottom of the striking cylinder. The connecting path is opened inside the bumper, and an air valve is disposed in the connecting path.

According to a fifth aspect of the present invention, in the first or fourth aspect , the cooling groove is formed inside the bumper, and the connecting path is opened inside the bumper. It supplies to the position corresponding to the groove | channel for cooling.

  According to the first aspect of the present invention, when cooling air is supplied to the inner lower part of the bumper, it is cooled quickly from the lower part of the inner peripheral surface of the bumper and the vicinity thereof. It is hard for cracks to occur and the life of the bumper can be extended. Further, since it is not necessary to increase the outer diameter of the bumper, the driving tool can be made compact.

In addition , since a part of the compressed air stored in the blowback chamber is supplied to the inside of the bumper via the connecting path, the structure can be simplified because it is not necessary to supply cooling air from the outside. Since the compressed air is blown in the blowback chamber, the cooling efficiency is good.

In addition , since cooling air is stored in the air storage chamber, a large amount of air can be sent to the bumper.

According to the second aspect of the present invention, the compressed air for cooling in the connection path is prevented from flowing back into the blowback chamber by the check valve. Therefore, the compressed air in the connection path is effectively used for cooling the bumper, and the cooling efficiency is good.

According to the invention of claim 3 , a part of the compressed air acting on the upper surface of the striking piston is supplied to the hollow portion of the driver, and at the same time the striking piston collides with the bumper, the compressed air flows from the communication hole to the inside of the bumper. Sent to the lower part a. Since the cooling is performed at almost the same timing as the heat generated by the impact of the striking piston against the bumper, the bumper hardly generates heat.

According to the fourth aspect of the invention, a sufficient amount of cooling air is sent at an optimum timing by setting the timing of supplying the compressed air from the compressed air supply source to the lower inner side of the bumper by the air valve. Can do.

According to the fifth aspect of the present invention, the cooling air is sent from the air supply means to the cooling groove, so that the vicinity of the inside of the bumper is directly cooled from the inside, and this cooling effect extends to the inner peripheral surface of the bumper. In addition, since a part of the cooling air is also sent to the inner peripheral surface of the bumper, the cooling efficiency is very good.

  FIG. 1 is a longitudinal sectional view of a driving tool. This driving tool has basically the same configuration as that of a normal nailing machine. In the figure, reference numeral 1 denotes a tool body. A grip 2 is formed on one side of the tool body 1, a nose part 3 is formed on the lower part, and a magazine 4 is continuously provided on one side of the nose part 3. The nail 5 in the magazine 4 is configured to be sequentially supplied to the injection port inside the nose portion 3 by a nail feeding mechanism (not shown).

  The end of the grip 2 is connected to a compressed air supply source (not shown) such as an air compressor so that the compressed air is supplied from the grip 2 to the air chamber 6 of the tool body 1.

  Inside the tool body 1, there is provided a striking mechanism comprising a striking cylinder 7, a striking piston 8 slidably accommodated in the striking cylinder 7, and a driver 9 integrally coupled to the striking piston 8. In addition, an annular main valve 10 is disposed on both sides of the upper portion of the impact cylinder 7 so as to be movable up and down in the valve housing 11. The lower end of the valve housing 11 is connected to the trigger valve 13 via a conduit 12.

  An annular exhaust chamber 14 is formed at the upper part between the striking cylinder 7 and the air chamber 6, and a blowback chamber 15 is formed at the lower part. The upper end of the exhaust chamber 14 can be opened and closed with the upper space of the striking piston 8 by the main valve 10.

  The trigger valve 13 is turned on and off by a trigger lever 17. When the trigger lever 17 pushes the valve stem 18 of the trigger valve 13, the main valve 10 can be opened and closed.

  The operation of the trigger lever 17 becomes effective only when the contact lever 19 is pushed up to the upper part 20 a of the contact arm 20. A lower portion (not shown) of the contact arm 20 is slidably disposed along the nose portion 3, and a lower end thereof is always biased by a spring so as to protrude below the lower end of the nose portion 3.

  Next, the operation mode of the driving tool will be described. First, when the lower end of the contact arm 20 is pressed against the material to be driven, the contact arm upper portion 20a is moved upward as shown in FIG. 2 to rotate the contact lever 19, and the trigger lever 17 is pulled up. Then, the valve stem 18 of the trigger valve 13 is pushed in, and the compressed air supplied into the valve housing 11 is exhausted from the lower periphery of the valve stem 18 of the trigger valve 13 through the pipe line 12. The compressed air in the air chamber 6 is supplied to the upper side of the striking cylinder 7. Since this compressed air acts on the upper surface of the striking piston 8 and drives the striking piston 8, the driver 9 strikes the nail 5 in the nose portion 3 and drives it into the workpiece.

  By the way, the air below the striking piston 8 is compressed in the striking cylinder 7 and is sent to the blowback chamber 15 from the through hole 21 formed on the side wall of the striking cylinder 7. An elastic body that prevents the backflow of the compressed air is attached to the through hole 21.

  When the trigger lever 17 is released after the nail driving is completed and the contact arm 20 is moved downward away from the material to be driven, as shown in FIG. 3, the valve stem 18 is also moved downward, and the trigger valve 13 is operated. Since the compressed air in the air chamber 6 is again sent from the pipe 12 to the valve housing 11 via the trigger valve 13, the main valve 10 moves upward, and the upper space of the striking cylinder 7 opens to the exhaust chamber 14. The pressure acting on the upper surface of the striking piston 8 is discharged from the upper part of the main valve 10 through the exhaust chamber 14 to the outside through the exhaust hole 22 and is therefore reduced. On the other hand, since the compressed air in the blowback chamber 15 is sent into the striking cylinder 7 from the through hole 16 of the striking cylinder 7 and acts on the bottom surface of the striking piston 8, the pressure difference with respect to the top and bottom surfaces of the striking piston 8 is reversed. Then, the striking piston 8 returns and moves upward. Thus, the initial state is restored, and the next nail driving is prepared.

  By the way, when the striking mechanism is driven as described above, the lower surface of the striking piston 8 impacts the bumper 23 arranged at the bottom of the striking cylinder 7 as shown in FIG. The bumper 23 is formed in a cylindrical shape by rubber or urethane resin. For this reason, repeating nail driving generates heat particularly in the lower part of the inner peripheral surface of the bumper 23 and the vicinity thereof, and deformation such as turning may occur.

  Therefore, a cooling device for cooling the bumper 23 is provided. This cooling device is constituted by an air supply means 24 for sending cooling air to the inside a of the bumper 23 or in the vicinity thereof.

  As such an air supply means 24, for example, as shown in FIGS. 1 to 3, the air supply means 24 may be configured by a connection path 25 that connects the blowback chamber 15 and the vicinity of the center of the bottom of the hitting cylinder 7. Then, by opening the connecting path 25 to the inner lower part a of the bumper 23, the compressed air compressed below the striking piston 8 at the time of nail driving enters the blowback chamber 15 from the through hole 21 on the side wall of the striking cylinder 7. At the same time, a part thereof is supplied to the inner lower part a of the bumper 23 through the connecting path 25.

  The cross-sectional area of the connecting path 25 may be increased, but the cross-sectional area may be decreased and a cooling air storage chamber 26 as shown in the above figure may be formed in the middle of the connecting path 25. According to this, since the compressed air stored in the blowback chamber 15 is temporarily stored in the air storage chamber 26, a large amount of compressed air can be supplied to the inner lower part a of the bumper 23 at a time.

  According to the above configuration, since the compressed air stored in the blowback chamber 15 can be sent into the bumper 23, the compressed air is sent to the inner lower part a of the bumper 23 almost simultaneously with the driving, so that it is cooled well. The

  As described above, when cooling air is supplied to the inner lower portion a of the bumper 23, the cooling is quickly performed from the lower portion of the inner peripheral surface of the bumper 23 and the vicinity thereof. It is difficult to generate and the life of the bumper 23 can be extended. Further, since it is not necessary to increase the outer diameter of the bumper 23, the driving tool can be made compact. Further, since the air compressed in the blowback chamber is blown, the cooling efficiency is good.

  Incidentally, as shown in FIGS. 4 and 5, it is preferable to provide a check valve 27 in the middle of the connecting path 25. In this case, the striking mechanism is activated from the initial state of FIG. 4 and the striking piston 8 is driven as shown in FIG. At the same time as being supplied from 21 to the blowback chamber 15, the air is stored in the air storage chamber 26 from the connection path 25 and further supplied to the inner lower part a of the bumper 23, and the bumper 23 is cooled. Thereafter, the striking piston 8 is returned to the initial position by the compressed air in the blowback chamber 15, and the pressure in the blowback chamber 15 is reduced. At that time, the compressed air for cooling in the air storage chamber 26 becomes the check valve 27. Is prevented from flowing back into the blowback chamber 15. Therefore, the compressed air in the connection path 5 is effectively used for cooling the bumper 23, and the cooling efficiency is good.

  Next, as another example of the air supply means 24, as shown in FIGS. 6 and 7, the inside of the driver 9 may be hollow and a communication hole 29 may be formed above the hollow portion 28. Good. The communication hole 29 may be formed at a position corresponding to the inner lower part a of the bumper 23 at the bottom dead center position of the driver 9 shown in FIG.

  According to the above configuration, a part of the compressed air acting on the upper surface of the striking piston 8 is supplied to the hollow portion 28 of the driver 9, and the striking piston 8 collides with the bumper 23 and at the same time, the compressed air is discharged from the communication hole 29 to the bumper. 23 to the inner lower part a. Since the inner peripheral surface of the bumper 23 is cooled at substantially the same timing as the heat generated by the impact of the striking piston 8 against the bumper 23, the bumper 23 is unlikely to generate heat.

  The air supply means 24 described above uses intake air, but the air supply means 24 is connected to the compressed air supply source 30 and the bottom of the striking cylinder 7 as shown in FIGS. The connecting path 31 (including the air storage chamber 26) to be connected may be configured such that the connecting path 31 is opened at the inner lower portion a of the bumper 23 and the air valve 32 is disposed in the connecting path 31.

  According to the above configuration, as shown in FIG. 9, the impact mechanism is driven and the air piston 32 is opened at the moment when the impact piston 8 impacts the bumper 23 or immediately thereafter, and the cooling compression is applied to the inner lower part a of the bumper 23. Air can be supplied.

  In this way, by setting the timing of supplying the air valve 32 from the compressed air supply source 30 to the inner lower portion a of the bumper 23 via the connection path 3, a sufficient amount of cooling air can be sent at an optimal timing. it can.

  Further, the exhaust may be used without using the intake air or the compressed air from the external compressed air supply source as in the above supply means. For example, as shown in FIG. 10, the air supply means 24 is configured by a connecting path 34 that connects the exhaust chamber 14 that is exhausted when the striking piston 8 moves back and the bottom of the striking cylinder 7. The connecting path 34 may be opened at the inner lower part a of the bumper 23.

  According to the above configuration, when the main valve 10 is operated to open the striking cylinder 7 to the exhaust chamber 14 after the striking mechanism is driven and the striking piston 8 impacts the bumper 23, the striking piston 8 is moved upward. The compressed air above the striking piston 8 is exhausted from the exhaust chamber 14 through the exhaust hole 22, and a part of the compressed air is supplied to the inner lower part a of the bumper 23 through the connection path 34. The peripheral surface and its vicinity are cooled.

  In this way, when the striking piston 8 returns, exhaust gas that has passed through the connection path 34 is supplied to the inner lower part a of the bumper 23 and does not use the intake air from the air chamber 6. The bumper 23 can be cooled without any influence on the operation of.

  In each of the above examples, the cooling air is sent to the inner lower part a of the bumper 23 through the air supply means 24. However, the heat generated by repeated collisions is caused by the inner peripheral surface of the bumper 23 and its inner surface. It is a neighborhood. Therefore, for example, as shown in FIG. 11 and FIGS. 12A to 12C, an annular recess 35 is formed on the lower surface of the bumper 23, and cooling grooves 36 are formed in the annular recess 35 at regular intervals, The air supply means 24 (any of those shown in FIGS. 1 to 10) may be opened below the annular recess 35.

  According to the above configuration, since the cooling air is sent from the air supply means 24 to the annular recess 35 and the cooling groove 36, the cooling air is directly cooled from the vicinity of the inner peripheral surface of the bumper 23. In addition to the peripheral surface, a part of the cooling air is also sent from the bottom of the bumper 23 to the inside a of the bumper 23, so that the cooling efficiency is very good.

  In this case, when the striking piston 8 collides with the bumper 23, the bumper 23 is filled with the compressed air almost simultaneously with the high pressure, so that the deformation of the bumper 23 at the time of the collision is minimized. be able to. It is preferable to apply to the example of FIG.

  In each of the above examples, the bumper has a shape in which the upper outer diameter is smaller than the lower outer diameter, the inner space is narrow at the center, and the upper and lower openings are larger. However, the bumper may be cylindrical and is not limited to the above example.

  The present invention is not limited to nailers. For example, if it has a striking mechanism, it can be applied to a driving tool for driving a fastener such as a screw driving machine. Of course, the present invention can be applied not only to a device using air pressure as a driving source but also to a driving tool driven by gas pressure or electric power.

It is a longitudinal cross-sectional view of an example of the cooling device of the bumper in the driving tool which concerns on this invention. It is a longitudinal cross-sectional view at the end of driving of the driving tool. It is a longitudinal cross-sectional view in the middle of the return | restoration of a striking piston after completion | finish of driving | operation of the said driving tool. It is a longitudinal cross-sectional view of the example which provided the check valve in the air supply means. It is a longitudinal cross-sectional view which shows the operation | movement aspect of FIG. It is a longitudinal cross-sectional view of the other example of an air supply means. It is a longitudinal cross-sectional view which shows the operation | movement aspect of FIG. It is a longitudinal cross-sectional view of the further another example of an air supply means. It is a longitudinal cross-sectional view which shows the operation | movement aspect of FIG. It is a secondary sectional view which shows the operation | movement aspect of another example of an air supply means. It is a secondary sectional view which shows the attachment state of the other example of a bumper. (A), (b), and (c) are a bottom view of the bumper, a cross-sectional view on the XX line, and a cross-sectional view on the YY line, respectively.

DESCRIPTION OF SYMBOLS 1 Tool main body 7 Stroke cylinder 8 Stroke piston 9 Driver 15 Blow back chamber 23 Bumper 24 Air supply means 25, 34 Connection path 27 Check valve

Claims (5)

A striking mechanism comprising a striking cylinder provided in the tool body, a striking piston slidably accommodated in the striking cylinder, and a driver integrally coupled to the striking piston is supplied from above the striking cylinder. The impacted piston is driven by the compressed air, the fastener is struck by the driver, and the compressed air is compressed outside the impact cylinder when the impact piston is driven. In a driving tool for supplying the blowback chamber to the generated blowback chamber and returning the striking piston upward by compressed air in the blowback chamber after the driving is completed, and exhausting the compressed air from the exhaust chamber to the outside.
An air supply means is provided for sending cooling air to the inner lower part of the hollow bumper disposed in the lower part of the hitting cylinder and receiving the lower surface of the hitting piston, or in the vicinity thereof .
The air supply means is configured by a connecting path that connects the blowback chamber and the bottom of the striking cylinder, and opens the connecting path inside the bumper.
A driving tool characterized in that an air storage chamber capable of temporarily storing cooling air is formed in the middle of the connection path . The driving tool according to claim 1 , wherein a check valve is provided in a middle portion of the connection path. A striking mechanism comprising a striking cylinder provided in the tool body, a striking piston slidably accommodated in the striking cylinder, and a driver integrally coupled to the striking piston is supplied from above the striking cylinder. The impacted piston is driven by the compressed air, the fastener is struck by the driver, and the compressed air is compressed outside the impact cylinder when the impact piston is driven. In a driving tool for supplying the blowback chamber to the generated blowback chamber and returning the striking piston upward by compressed air in the blowback chamber after the driving is completed, and exhausting the compressed air from the exhaust chamber to the outside.
An air supply means is provided for sending cooling air to the inner lower part of the hollow bumper disposed in the lower part of the hitting cylinder and receiving the lower surface of the hitting piston, or in the vicinity thereof.
The air supply means, and characterized in that causes opening the upper end of the interior of the driver as a hollow, was constructed by forming a communicating hole in the wall portion corresponding to the inside of the bumper at the bottom dead center position of the driver the driving tool. A striking mechanism comprising a striking cylinder provided in the tool body, a striking piston slidably accommodated in the striking cylinder, and a driver integrally coupled to the striking piston is supplied from above the striking cylinder. The impacted piston is driven by the compressed air, the fastener is struck by the driver, and the compressed air is compressed outside the impact cylinder when the impact piston is driven. In a driving tool for supplying the blowback chamber to the generated blowback chamber and returning the striking piston upward by compressed air in the blowback chamber after the driving is completed, and exhausting the compressed air from the exhaust chamber to the outside.
An air supply means is provided for sending cooling air to the inner lower part of the hollow bumper disposed in the lower part of the hitting cylinder and receiving the lower surface of the hitting piston, or in the vicinity thereof.
Characterized in that said air supply means is constituted by a connecting passage that connects the bottom of the compressed air supply source and the driving cylinder, the connecting path with is opened to the inside of the bumper, and arranged the air valve in the connecting passage A driving tool. To form a cooling groove inside said bumper, the connecting path, instead of being open to the inside of the bumper, and supplies the position corresponding to the cooling grooves in the bottom of the striking cylinder, according to claim 1 or 4. The driving tool according to 4 .

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