JP2019188536A - Driving tool - Google Patents

Abstract

To provide a nail driver which enables a gas in a striking cylinder to be exhausted without causing the gas to flow through a combustion chamber.SOLUTION: A nail driver includes: a striking cylinder 2 which is actuated by combustion pressure of a mixture gas of compression air and a fuel; a combustion chamber 3 in which the mixture gas of the compression air and the fuel is combusted; a head valve 4 which opens or closes between the striking cylinder 2 and the combustion chamber 3; a striking cylinder exhaust port 23 which allows communication between the striking cylinder 2 and the outside; and an exhaust valve 7 which opens or closes the striking cylinder exhaust port 23.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a driving tool that burns a compressed gas mixture of an oxidant and fuel and is driven by the combustion pressure.

  As a compressed oxidizer, a driving tool called a nailing machine is known in which compressed air is used as a power source and a piston is operated by a striking cylinder and a driver coupled to the piston is driven to drive a fastener such as a nail. Yes.

  On the other hand, there is known a driving tool in which a mixed gas of air and fuel is burned, a driving cylinder is operated with the combustion pressure, and a fastener such as a nail is driven. In the gas combustion type driving tool, the combustion pressure can be further increased by burning the mixed gas whose pressure has been increased in advance. However, when compressed air is supplied to the combustion chamber in order to generate a mixed gas with increased pressure, the striking cylinder is operated with the pressure of the compressed air before the mixed gas is combusted.

  Therefore, a driving tool including a combustion chamber for burning a mixed gas of compressed air and fuel and a head valve mechanism for partitioning the striking cylinder so as to be opened and closed has been proposed (for example, see Patent Document 1).

  Further, in the driving tool that operates the striking cylinder with the combustion pressure, an exhaust port is provided in the combustion chamber in order to exhaust the gas remaining in the combustion chamber to the outside after the piston of the striking cylinder is operated. In addition, a technology has been proposed in which a check valve is provided at a portion that partitions the combustion chamber and the striking cylinder so that gas in the striking cylinder can be sent from the check valve to the combustion chamber and exhausted from the exhaust port of the combustion chamber. (For example, refer to Patent Document 2).

Japanese Patent Laid-Open No. 51-58768 Japanese Patent No. 4935978

  In a driving tool that operates a striking cylinder with a combustion pressure, a mixed gas of compressed air and fuel is combusted in the combustion chamber, so that the head valve mechanism opens a space between the striking cylinder and the combustion chamber. When the gas flows into the striking cylinder and the pressure in the combustion chamber decreases, the head valve mechanism is closed. For this reason, with the operation of the piston returning from the bottom dead center position to the top dead center position, the gas in the striking cylinder cannot be exhausted to the outside from the exhaust port provided in the combustion chamber, and the piston is reliably It is difficult to return to the position.

  Therefore, an exhaust port provided with a check valve in the part that partitions the combustion chamber and the striking cylinder, and sending the gas in the striking cylinder from the check valve to the combustion chamber, the gas in the striking cylinder is provided in the combustion chamber. Can be exhausted to the outside. However, in a configuration in which a check valve is provided at a portion that partitions the combustion chamber and the striking cylinder, a pressure difference between the combustion chamber and the striking cylinder is required to open the check valve. For this reason, when the pressure in the striking cylinder decreases due to the gas in the striking cylinder passing through the check valve and exhausted to the outside from the exhaust port of the combustion chamber, the pressure in the striking cylinder may be reduced depending on the pressure in the combustion chamber. The check valve may close before the pressure drops to atmospheric pressure, and the residual pressure in the striking cylinder cannot reliably return the piston to the top dead center position. Moreover, the structure becomes complicated by providing the check valve, and the combustion chamber is enlarged in order to secure the volume of the combustion chamber.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a driving tool that can exhaust the gas in the striking cylinder without passing through the combustion chamber.

  In order to solve the above-mentioned problems, the present invention burns a striking cylinder having a piston that operates at a combustion pressure of a mixed gas of compressed oxidant and fuel, and a mixed gas of compressed oxidant and fuel. The driving tool includes a combustion chamber, a valve body that opens and closes between the striking cylinder and the combustion chamber, and a striking cylinder exhaust valve that opens and closes between the striking cylinder and the outside.

  In the present invention, the compressed gas mixture of oxidant and fuel is burned in the combustion chamber, the valve body opens between the striking cylinder and the combustion chamber, and high-temperature and high-pressure gas flows from the combustion chamber into the striking cylinder. Then, the piston moves from the top dead center position to the bottom dead center position, and driving is performed. When the pressure between the striking cylinder and the combustion chamber is closed by the valve body due to the pressure in the combustion chamber decreasing, the piston returns to the top dead center position from the bottom dead center position. The exhaust valve exhausts air from the striking cylinder.

  In the present invention, even if the space between the striking cylinder and the combustion chamber is blocked by the valve body, the piston returns to the top dead center position from the bottom dead center position, and the gas in the striking cylinder is exhausted to the outside by the exhaust valve. Therefore, the piston can be reliably returned to the top dead center position. In addition, it is not necessary to provide a check valve at the part that separates the combustion chamber and the striking cylinder, and the gas in the striking cylinder can be exhausted to the outside regardless of the pressure in the combustion chamber. Since it can return to a dead center position and it is not necessary to provide a check valve, the structure can be simplified and the enlargement of the combustion chamber can be suppressed.

It is a principal part block diagram which shows an example of the nailing machine of this Embodiment. It is a whole lineblock diagram showing an example of a nailing machine of this embodiment. It is a whole lineblock diagram showing an example of a nailing machine of this embodiment. It is a principal part block diagram which shows an example and operation example of a nailing machine of this Embodiment. It is a principal part block diagram which shows an example and operation example of a nailing machine of this Embodiment. It is a principal part block diagram which shows an example and operation example of a nailing machine of this Embodiment. It is a principal part block diagram which shows an example and operation example of a nailing machine of this Embodiment.

  Hereinafter, an embodiment of a nailing machine which is an example of a driving tool of the present invention will be described with reference to the drawings.

<Configuration example of nailing machine of the present embodiment>
FIG. 1 is a main configuration diagram illustrating an example of a nail driver according to the present embodiment, and FIGS. 2 and 3 are overall configuration diagrams illustrating an example of a nail driver according to the present embodiment. 4-7 is a principal part block diagram which shows an example and operation example of the nailing machine of this Embodiment.

  The nailing machine 1A according to the present embodiment includes a main body portion 10 and a handle portion 11 that extends from the main body portion 10 and is gripped by a hand. The nailing machine 1 </ b> A includes a nose portion 12 on one side of the main body portion 10 where a fastener is driven out. In the following description, in consideration of the usage pattern of the nailing machine 1A, the side on which the nose portion 12 is provided is referred to as the lower side, and the side opposite to the side on which the nose portion 12 is provided is referred to as the upper side. The side on which the handle portion 11 is provided is the rear side, and the opposite side to the side on which the handle portion 11 is provided is the front side.

  In the nailing machine 1A, a tank mounting portion 13 to which a fuel tank (not shown) filled with fuel is detachably mounted is provided in a form substantially parallel to the lower portion of the handle portion 11. In the nailing machine 1 </ b> A, a magazine 14 sharing a fastener with the nose portion 12 is provided below the tank mounting portion 13. Further, in the nailing machine 1A, an air plug 15 to which an air hose to which compressed air is supplied from a supply source such as an air compressor is connected as a compressed oxidizer is provided in the tank mounting portion 13 in this example.

  Further, in the nail driver 1A, an operation trigger 16 for operating the nail driver 1A is provided in the handle portion 11, and a battery mounting portion 18 to which a battery 17 serving as a power source of the nail driver 1A is attached is provided in the handle portion 11. .

  The nailing machine 1A includes a striking cylinder 2 that operates with a combustion pressure of a mixed gas of compressed air and fuel, a combustion chamber 3 that combusts a mixed gas of compressed air and fuel, a striking cylinder 2 and a combustion chamber 3. A head valve 4 that opens and closes the head valve 4 and a valve support 5 that supports the head valve 4 are provided.

  The striking cylinder 2 is an example of a striking mechanism, and includes a driver 20 that ejects a fastener supplied from the magazine 14 to the nose portion 12 and a piston 21 provided with the driver 20. The striking cylinder 2 is provided with a cylindrical space in which the piston 21 can slide, and the driver 20 moves along the extending direction of the nose portion 12 by the reciprocating motion of the piston 21.

  The striking cylinder 2 is provided with a piston position restricting portion 2a having a tapered shape whose diameter increases upward at the periphery of the upper end. When the piston 21 moves upward, the piston ring 21a provided on the outer peripheral surface of the piston 21 is locked to the piston position restricting portion 2a, whereby the top dead center position of the piston 21 is defined. The locking of the piston 21 by the piston position restricting portion 2a is released by the force by which the piston 21 is pushed by the combustion pressure, and the piston 21 can be moved by the combustion pressure.

  Further, the striking cylinder 2 includes a buffer material 22 to which the piston 21 is applied. The cushioning material 22 is made of an elastic member and is provided in the lower part of the striking cylinder 2. In the striking cylinder 2, the piston 21 moved downward by the operation of driving out the fastener hits the buffer material 22, whereby the bottom dead center position of the piston 21 is defined, and the movement range of the driver 20 and the piston 21 is restricted.

  The combustion chamber 3 is provided in the upper part of the striking cylinder 2 along the axial direction of the driver 20 and the piston 21 that are the axial direction of the striking cylinder 2. The striking cylinder 2 and the combustion chamber 3 are partitioned by a partition 50, and a striking cylinder inlet 51 through which the burned high-temperature and high-pressure air passes is provided. The striking cylinder inlet 51 is an example of a striking mechanism inlet, and is configured by providing circular openings on the axes of the driver 20 and the piston 21 in the axial direction of the striking cylinder 2.

  In the combustion chamber 3, a valve support 5 is provided around the blow cylinder inlet 51, and a ring-shaped space is formed around the valve support 5.

  The head valve 4 is an example of a valve body, and is composed of a cylindrical metal member. As shown in FIG. 6 and FIG. 7, the head valve 4 is closed at the lower end surface along the axial direction of the cylinder to form a circular and flat valve surface 40. The head valve 4 is configured such that the diameter of the valve surface 40 is larger than that of the striking cylinder inlet 51, and the striking cylinder inlet 51 is closed when the valve surface 40 is in contact with the partition portion 50.

  The head valve 4 includes a first seal part 41 and a second seal part 42. The first seal portion 41 is an example of a seal portion, and is provided on the outer periphery of the valve surface 40 along the axial direction that is the moving direction of the head valve 4, and the first seal member 41 a is attached to the first seal portion 41. The first sealing material 41a is composed of a metal ring called a piston ring. In the first seal portion 41, a groove into which the first seal material 41a is fitted is formed in the circumferential direction, and when the first seal material 41a is attached, the first seal material 41a protrudes from the circumferential surface by a predetermined amount. To do. In the present example, two first sealing portions 41 a are attached to the first sealing portion 41 along the axial direction of the head valve 4.

  The second seal portion 42 is an example of a seal portion, and is provided on the outer periphery of the head valve 4 at a predetermined distance from the first seal portion 41 along the axial direction of the head valve 4. 42a is attached. The second sealing material 42a is a so-called O-ring made of an elastic body such as rubber. In the second seal portion 42, a groove into which the second seal material 42a is fitted is formed in the circumferential direction, and when the second seal material 42a is attached, the second seal material 42a protrudes from the circumferential surface by a predetermined amount. To do.

  In the head valve 4, the first seal portion 41 and the second seal portion 42 protrude outward from the circumferential surface of the head valve 4, and the second seal portion 42 is in relation to the first seal portion 41. The diameter is large. The surface of the second seal portion 42 that faces the first seal portion 41 is an operation surface 43 that is pressed by high-temperature and high-pressure gas. The operation surface 43 is a ring-shaped surface.

  The head valve 4 is urged toward the partition portion 50 by a spring 44. The spring 44 is an example of an urging member, and is configured by a coil spring. The axis of the spring 44 is on the axis of the driver 20 and the piston 21 on the axis of the striking cylinder 2, that is, the head valve 4 and the striking cylinder inlet 51. It is provided on the same axis. The spring 44 enters the recessed portion 45 formed in the head valve 4 along the axial direction that is the moving direction of the head valve 4 so that the head valve 4 and a part of the spring 44 overlap in the axial direction. Arranged. Such an arrangement is called an overlap arrangement. Further, since the spring 44 enters the recess 45 of the head valve 4, the spring 44 has a smaller diameter than the head valve 4, and the spring 44 can have a smaller diameter than the striking cylinder 2.

  The force that pushes the head valve 4 by the spring 44 is a force that keeps the valve surface 40 in contact with the partition portion 50 in a state where high-temperature and high-pressure gas does not act on the operating surface 43.

  The head valve 4 is movably supported by a valve support 5.

  The valve support 5 is an example of a valve support and is formed of a cylindrical metal member. As shown in FIGS. 6 and 7, the valve support 5 is integrally provided with a partition portion 50 at a lower portion along the axial direction of the cylinder in this example. When the head valve 4 is inserted into a cylindrical inner space, the valve support 5 is in sliding contact with the first seal member 41a of the first seal portion 41 of the head valve 4 and the second seal portion 42. The second sealing material 42a is in sliding contact. The valve support 5 is provided at each of the seals at a portion where the first seal member 41a of the first seal portion 41 of the head valve 4 is slidably contacted and a portion where the second seal member 42a of the second seal portion 42 is slidably contacted. The inner diameter differs depending on the part.

  When the head valve 4 is inserted into the valve support 5, an operation space 52 is formed between the first seal portion 41 and the second seal portion 42 of the head valve 4 and the inner surface of the valve support 5. The working space 52 is an annular space.

  The valve support 5 includes a head valve inlet 53 that connects the combustion chamber 3 and the working space 52. The head valve inlet 53 is configured by providing an opening penetrating the valve support 5 in the vicinity of the first seal portion 41 in a state where the valve surface 40 of the head valve 4 is in contact with the partition portion 50. The By forming the head valve inlet 53 on the side surface of the valve support 5, the flow path connecting the combustion chamber 3 and the working space 52 is not complicated, and an increase in inflow resistance can be prevented.

  As shown in FIG. 6, the head valve inlet 53 is in a state where the valve surface 40 of the head valve 4 is in contact with the partition portion 50, that is, a state where the striking cylinder inlet 51 is closed by the head valve 4. Then, it connects with the working space 52.

  On the other hand, when the high-temperature and high-pressure gas acts on the operating surface 43 of the head valve 4 and the head valve 4 moves upward as shown in FIG. 7, the striking cylinder inlet 51 opens and the head valve inlet 53 is connected to the striking cylinder inlet 51.

  Air passing through the head valve inlet 53 is high-temperature and high-pressure air generated by burning a mixed gas of compressed air and fuel in the combustion chamber 3. Since the high-temperature and high-pressure gas has a lower viscosity than air at normal temperature and pressure, even if the opening area of the head valve inlet 53 is small, an increase in resistance to the gas flow is suppressed.

  The first seal portion 41 is provided with a first seal material 41 a on the outer periphery, and the first seal material 41 a is in contact with the inner surface of the valve support 5. Since the first sealing material 41a is fitted in the groove, the portion exposed to the working space 52 is minimized.

  The second seal portion 42 is provided with a second seal material 42 a on the outer periphery, and the second seal material 42 a contacts the inner surface of the valve support 5. Since the second sealing material 42a is fitted in the groove, the portion exposed to the working space 52 is minimized.

  The valve support 5 includes a cushioning material 54 to which the head valve 4 is applied. The buffer material 54 is made of an elastic member and is provided on the upper portion of the head valve 4. In the valve support 5, the moving range of the head valve 4 is restricted when the head valve 4 moved by the high-temperature and high-pressure gas acting on the operating surface 43 of the head valve 4 hits the buffer material 54. Although the movement range of the head valve 4 is regulated by the buffer material 54, when the head valve 4 hits the buffer material 54, the shock valve 54 absorbs an impact by elastic deformation, so the height of the head valve inlet 53 is It is preferable to set the stroke of the head valve 4 or less. Thereby, when the head valve 4 moves to a position where it hits the buffer material 54, the head valve 4 can be prevented from being exposed to the head valve inlet 53, and the entire head valve inlet 53 is opened. Thus, the output can be stabilized by making the opening amount of the head valve inlet 53 constant.

  The upper opening of the combustion chamber 3 is sealed by the head portion 30. The head unit 30 is provided with an ignition device 31. The head unit 30 is provided with a fuel supply port and a compressed air supply port (not shown). Further, the shock absorber 54 is provided in contact with the head portion 30 so that the impact applied to the head portion 30 is buffered, the durability of the parts is improved, the bolts that attach the head portion 30 to the combustion chamber 3 are prevented from loosening, and the electrical noise An effect such as reduction of the above can be obtained.

  The nailing machine 1 </ b> A includes a blowback chamber 6 that stores a gas for returning the driver 20 and the piston 21 of the striking cylinder 2. The blowback chamber 6 is provided around the hitting cylinder 2 and is connected to the inside of the hitting cylinder 2 through an inflow / outlet port 60 provided in the vicinity of the cushioning material 22.

  The nailing machine 1 </ b> A includes an exhaust valve 7 that exhausts the gas in the impact cylinder 2 and the combustion chamber 3. The exhaust valve 7 is an example of an exhaust valve. The exhaust valve 7 is provided on one side of the impact cylinder 2 with respect to the extending direction of the handle portion 11, the exhaust piston 71 pushed by the gas flowing into the blowback chamber 6, and the impact cylinder 2. A first exhaust valve 72 that opens and closes the impact cylinder exhaust port 23 formed in the combustion chamber 3, a second exhaust valve 73 that opens and closes the combustion chamber exhaust port 32 formed in the combustion chamber 3, an exhaust piston 71, and a first exhaust valve 71. A valve rod 74 connecting the exhaust valve 72 and the second exhaust valve 73 is provided.

  In the exhaust valve 7, an exhaust piston 71, a first exhaust valve 72, a second exhaust valve 73, and a valve rod 74 are integrally formed of a metal material. In the exhaust valve 7, the movement of the exhaust piston 71 is transmitted to the first exhaust valve 72 and the second exhaust valve 73 via the valve rod 74, and the first exhaust valve 72 and the second exhaust valve 73 are interlocked. Move.

  Further, the exhaust valve 7 includes an exhaust cylinder 75 connected to the blowback chamber 6, and an exhaust flow path forming cylinder 76 connected to the striking cylinder exhaust port 23 and the combustion chamber exhaust port 32. The exhaust cylinder 75 is provided with a cylindrical space in which the exhaust piston 71 can slide on one side of the impact cylinder 2 with respect to the extending direction of the handle portion 11. 7 moves along the extending direction of the valve rod 74.

  The exhaust passage forming cylinder 76 has a cylindrical space in which the first exhaust valve 72 and the second exhaust valve 73 are slidable on one side of the striking cylinder 2 with respect to the extending direction of the handle portion 11. It is provided and extends along the moving direction of the piston 21.

  The striking cylinder exhaust port 23 is an example of an exhaust port, and an outer opening 23a that penetrates between the exhaust passage forming cylinder 76 and the outside, and an inner opening 23b that penetrates between the exhaust passage forming cylinder 76 and the striking cylinder 2. The outside and the inside of the striking cylinder 2 are communicated with each other via an exhaust passage forming cylinder 76.

  The striking cylinder exhaust port 23 is an operation in which the piston 21 returns from the bottom dead center position to the top dead center position, so that the gas in the striking cylinder 2 can be exhausted to the outside. It is provided opposite to the point position. Further, the outer opening 23a of the striking cylinder exhaust port 23 opens toward the side of the striking cylinder 2, and the outer opening 23a and the inner opening 23b are arranged in a straight line.

  The combustion chamber exhaust port 32 is an example of an exhaust port, and an outer opening 32 a that penetrates between the exhaust passage forming cylinder 76 and the outside, and an inner opening 32 b that penetrates between the exhaust passage formation cylinder 76 and the combustion chamber 3. And the outside and the inside of the combustion chamber 3 are communicated with each other via an exhaust passage forming cylinder 76. The exhaust flow path forming cylinder 76 and the combustion chamber 3 are partitioned by a wall 76a except for the portion where the inner opening 32b is provided.

  The combustion chamber exhaust port 32 has an outer opening 32 a that opens toward the side of the striking cylinder 2, and the outer opening 32 a and the inner opening 32 b are offset up and down along the direction of movement of the second exhaust valve 73. Is done.

  The first exhaust valve 72 is an example of a striking cylinder exhaust valve, has a substantially cylindrical shape that matches the inner peripheral surface of the exhaust flow path forming cylinder 76, and has a diameter that allows sliding contact with the inner surface of the exhaust flow path forming cylinder 76. Provided between the pair of sealing portions 72a and 72b and the pair of sealing portions 72a and 72b, is substantially cylindrical with a smaller diameter than the sealing portions 72a and 72b, and between the inner surface of the exhaust flow path forming cylinder 76 A flow path forming part 72c in which a space is formed is provided.

  The second exhaust valve 73 is an example of a combustion chamber exhaust valve, has a substantially disk shape that matches the inner peripheral surface of the exhaust flow path forming cylinder 76, and includes a sealing member 73a on the outer peripheral surface. The sealing member 73 a is configured by, for example, an O-ring, and the sealing member 73 a is in sliding contact with the inner peripheral surface of the exhaust flow path forming cylinder 76.

  As shown in FIG. 1, when the flow path forming portion 72 c moves to a position facing the outer opening 23 a and the inner opening 23 b of the striking cylinder exhaust port 23, the first exhaust valve 72 opens the outer opening of the striking cylinder exhaust port 23. 23a and the inner opening 23b communicate with each other in a space formed between the inner surface of the exhaust flow path forming cylinder 76 and the flow path forming portion 72c, and the striking cylinder exhaust port 23 is opened.

  When the flow path forming portion 72c moves to a position facing the outer opening 23a and the inner opening 23b of the striking cylinder exhaust port 23, the exhaust flow path forming cylinder 76 on the upper side of the flow path forming portion 72c becomes one sealing portion 72a. The lower exhaust flow path forming cylinder 76 is sealed with the other sealing portion 72b.

  The sealing parts 72a and 72b are made of metal and do not include a sealing member such as an O-ring. However, the sealing structure depends on the outer diameter of the sealing parts 72a and 72b and the inner diameter of the exhaust passage forming cylinder 76. Is realized.

  When the first exhaust valve 72 opens the striking cylinder exhaust port 23, the second exhaust valve 73 moves to the upper side of the inner opening 32b of the combustion chamber exhaust port 32 as shown in FIG. The exhaust passage forming cylinder 76 communicates between the inner opening 32b and the outer opening 32a of the combustion chamber exhaust port 32, and the combustion chamber exhaust port 32 is opened.

  In addition, in a state where the second exhaust valve 73 is moved above the inner opening 32 b of the combustion chamber exhaust port 32, the sealing portion of the first exhaust valve 72 is provided below the outer opening 32 a of the combustion chamber exhaust port 32. 72 a is located, and the space between the blow cylinder exhaust port 23 and the combustion chamber exhaust port 32 is sealed by the sealing portion 72 a of the first exhaust valve 72.

  Thus, the first exhaust valve 72, the striking cylinder exhaust port 23, and the exhaust flow path forming cylinder 76 constitute an exhaust valve, and the second exhaust valve 73, the combustion chamber exhaust port 32, and the exhaust flow path forming cylinder 76 are combusted. A chamber exhaust valve is configured.

  The first exhaust valve 72, the striking cylinder exhaust port 23, and the exhaust flow path forming cylinder 76 are provided on one side of the striking cylinder 2, and the striking cylinder exhaust port 23 faces the side of the striking cylinder 2. Further, the second exhaust valve 73, the combustion chamber exhaust port 32, and the exhaust flow path forming cylinder 76 are provided on one side of the combustion chamber 3, and the combustion chamber exhaust port 32 faces the side of the combustion chamber 3.

  Further, the exhaust valve 7 includes a buffer material 77 against which the exhaust piston 71 is applied. The buffer material 77 is formed of an elastic member. The movement range of the exhaust valve 7 is restricted when the exhaust piston 71 hits the buffer material 77.

  Further, the exhaust valve 7 includes a spring 79 that biases the valve rod 74 in such a direction that the first exhaust valve 72 closes the striking cylinder exhaust port 23 and the second exhaust valve 73 closes the combustion chamber exhaust port 32. The spring 79 is an example of an urging member. In this example, the spring 79 is formed of a compression coil spring, and is inserted between a spring receiving portion 24 formed on the side surface of the striking cylinder 2 and a spring presser 74 a attached to the valve rod 74.

  The spring retainer 74a moves integrally with the valve rod 74. When the valve rod 74 moves in the direction in which the spring 79 is compressed by the spring retainer 74a, the first exhaust valve 72 opens the striking cylinder exhaust port 23, and the second An exhaust valve 73 opens the combustion chamber exhaust port 32. When the valve rod 74 moves in the direction in which the spring 79 extends, the first exhaust valve 72 closes the striking cylinder exhaust port 23 and the second exhaust valve 73 closes the combustion chamber exhaust port 32.

  The nailing machine 1 </ b> A includes a contact member 8 in a nose portion 12. The contact member 8 is provided so as to be movable along the extending direction of the nose portion 12, and is biased by the spring 80 in a direction protruding from the nose portion 12. The contact member 8 is connected to the exhaust valve 7 via a link 81. The link 81 is attached to the side surface of the striking cylinder 2 so as to be rotatable about the shaft 81d as a fulcrum, and one end side is connected to the contact member 8. The link 81 is urged by a spring 80 constituted by a tension coil spring, whereby the contact member 8 rotates in a direction protruding from the nose portion 12.

  Further, the link 81 is connected to the exhaust valve 7 through an elongated hole portion 78 formed in the valve rod 74 at the other end side. The elongated hole portion 78 is configured by an opening extending along the moving direction of the valve rod 74, and is configured so that the valve rod 74 can move in a state where the position of the link 81 is fixed by the contact member 8.

  As a result, the link 81 rotates in conjunction with the movement of the contact member 8 and the exhaust valve 7 operates. In addition, the link 81 and the valve rod 74 are disconnected in the shape of the link 81 and the elongated hole portion 78 and the position of the link 81 is fixed by the contact member 8, and the exhaust gas is exhausted by the gas flowing into the blowback chamber 6. Valve 7 is activated.

<Operation example of the nailing machine of the present embodiment>
Next, the operation of the nailing machine 1A of the present embodiment will be described with reference to the drawings. In the initial state, the operation trigger 16 is not pulled, and the contact member 8 is not pushed by the driven material, and is in an initial position that is biased by the spring 80 and protrudes from the nose portion 12.

  In a state where the contact member 8 is in the initial position, the link 81 is urged by the spring 80 to push the elongated hole portion 78 of the valve rod 74 and the valve rod 74 moves in a direction to compress the spring 79. As shown in FIG. 1, the exhaust valve 7 moves to a position where the flow path forming portion 72c of the first exhaust valve 72 faces the outer opening 23a and the inner opening 23b of the striking cylinder exhaust port 23, and the striking cylinder exhaust port. 23 opens. Further, the second exhaust valve 73 is interlocked with the first exhaust valve 72 and moves to the upper side of the inner opening 32b of the combustion chamber exhaust port 32, so that the inner opening 32b and the outer opening 32a of the combustion chamber exhaust port 32 are moved. Are communicated by an exhaust passage forming cylinder 76, and the combustion chamber exhaust port 32 is opened. Thereby, the striking cylinder 2 and the combustion chamber 3 are in a state opened to the atmosphere.

  The head valve 4 is pressed by the spring 44 and is in a state where the valve surface 40 is in contact with the partition portion 50, that is, a state where the striking cylinder inlet 51 is closed by the head valve 4. In this state, the head valve inlet 53 is connected to the working space 52.

  When the contact member 8 is pressed against the material to be driven, the link 81 rotates in the direction in which the spring 80 is extended, so that the valve rod 74 moves in the direction in which the spring 79 extends following the rotation of the link 81. The movement 8 is transmitted to the exhaust valve 7 through the link 81.

  As shown in FIG. 4, the exhaust valve 7 moves to a position where the sealing portion 72 a of the first exhaust valve 72 faces the outer opening 23 a and the inner opening 23 b of the striking cylinder exhaust port 23, and the striking cylinder exhaust port 23. Closes. Further, in conjunction with the first exhaust valve 72, the second exhaust valve 73 moves between the outer opening 32a and the inner opening 32b of the combustion chamber exhaust port 32, and the combustion chamber exhaust port 32 is closed. Thereby, the striking cylinder 2 and the combustion chamber 3 are sealed.

  In conjunction with the operation of the contact member 8 and the operation trigger 16, an air valve and a fuel valve (not shown) are opened, and vaporized fuel and compressed air are supplied to the combustion chamber 3. For example, when the contact member 8 is pressed against the workpiece, a fuel valve (not shown) is opened, and when the operation trigger 16 is operated, an air valve (not shown) is opened. If the contact member 8 is pressed against the workpiece and the operation trigger 16 is operated, an air valve and a fuel valve (not shown) may be opened at a predetermined timing. Further, when the contact member 8 is pressed against the material to be driven, an air valve and a fuel valve (not shown) may be opened at a predetermined timing.

  When compressed air is supplied to the combustion chamber 3, the pressure in the combustion chamber 3 increases. However, when the pressure in the combustion chamber 3 is increased by the compressed air, the head valve 4 is pressed by the spring 44 and keeps the valve surface 40 in contact with the partition 50, and the striking cylinder inlet 51 is closed by the head valve 4. It is done. Therefore, even if the pressure in the combustion chamber 3 increases due to the supply of compressed air, the pressure does not increase in the striking cylinder 2 and the piston 21 does not operate.

  When the ignition device 31 is activated at a predetermined timing after the contact member 8 is pressed against the workpiece and the operation trigger 16 is operated to open an air valve and a fuel valve (not shown), the compression in the combustion chamber 3 is performed. A mixed gas of air and fuel burns. When the mixed gas burns in the combustion chamber 3, the pressure in the combustion chamber 3 rises, and high-temperature and high-pressure gas flows into the working space 52 from the head valve inlet 53 of the valve support 5.

  When the pressure in the working space 52 rises, high-temperature and high-pressure gas acts on the working surface 43 of the head valve 4, so that the head valve 4 moves upward while compressing the spring 44. Here, when the pressure in the working space 52 rises, the pressure is also applied to the surface of the first seal portion 41 that faces the working space 52. However, since the area of the operating surface 43 is larger, the head valve 4 is raised while compressing the spring 44.

  As shown in FIG. 7, when the head valve 4 moves upward, the striking cylinder inlet 51 is opened, and the head valve inlet 53 is connected to the striking cylinder inlet 51. As a result, high-temperature and high-pressure gas flows from the combustion chamber 3 through the blow cylinder inlet 51 into the blow cylinder 2 and the pressure of the blow cylinder 2 increases.

  When the pressure of the striking cylinder 2 increases, the piston 21 is pushed, the piston 21 and the driver 20 move in the direction of driving out the fastener, and the fastener driving operation is performed. When the piston 21 and the driver 20 move in the direction of driving out the fastener, the gas (air) in the piston lower chamber 25a, which is one chamber in the striking cylinder 2 partitioned by the piston 21, flows from the inlet / outlet port 60 to the blowback chamber 6. Flow into. Further, since the piston 21 passes through the inflow / outlet port 60 while compressing and deforming the buffer material 22, a part of the high-temperature and high-pressure gas that has driven the piston 21 flows into the blowback chamber 6.

  When the gas (air) in the blow cylinder 2 flows into the blowback chamber 6 and the pressure in the blowback chamber 6 increases, the exhaust piston 71 of the exhaust valve 7 is pushed as shown in FIG. The exhaust valve 7 and the link 81 are connected through a long hole 78 formed in the valve rod 74, and the link 81 and the valve rod 74 are connected in a state where the position of the link 81 is fixed by the contact member 8. Is cut off, and the exhaust valve 7 can move to a position where it collides with the buffer material 77. Since the movement amount of the exhaust valve 7 is regulated by the buffer material 77, the durability of the exhaust valve 7 is improved.

  Thus, when the exhaust piston 71 of the exhaust valve 7 is pushed, the first exhaust valve 72 moves to a position where the flow path forming portion 72c faces the outer opening 23a and the inner opening 23b of the striking cylinder exhaust port 23, The blow cylinder outlet 23 opens. Further, the second exhaust valve 73 is interlocked with the first exhaust valve 72 and moves to the upper side of the inner opening 32b of the combustion chamber exhaust port 32, so that the inner opening 32b and the outer opening 32a of the combustion chamber exhaust port 32 are moved. Are communicated by an exhaust passage forming cylinder 76, and the combustion chamber exhaust port 32 is opened.

  Therefore, the striking cylinder 2 and the combustion chamber 3 are opened to the atmosphere, and the gas in the combustion chamber 3 is exhausted from the combustion chamber exhaust port 32 to the outside. Further, high-temperature and high-pressure gas flows from the combustion chamber 3 through the striking cylinder inlet 51 into the striking cylinder 2, and the pressure in the combustion chamber 3 decreases, so that the head valve 4 is pressed by the spring 44 and the valve The surface 40 moves to a position in contact with the partition 50, and the striking cylinder inlet 51 is closed by the head valve 4.

  Further, when the piston 21 and the driver 20 move in the direction of driving out the fastener, and the piston 21 moves to the bottom dead center and hits the buffer material 22, the piston 21 and the driver 20 try to move upward due to the elasticity of the buffer material 22. . When the piston 21 passes through the inlet / outlet port 60 and moves to the upper side of the inlet / outlet port 60, the gas (air) in the blowback chamber 6 whose pressure is increasing flows into the striking cylinder 2 and pushes the piston 21. . When the piston 21 is pushed, the gas in the piston upper chamber 25b, which is the other chamber in the striking cylinder 2 partitioned by the piston 21, is exhausted to the outside from the striking cylinder exhaust port 23, and the piston 21 and the driver 20 are top dead center. Return to.

  When the contact member 8 is separated from the driven material, the link 81 is urged by the spring 80 to push the elongated hole portion 78 of the valve rod 74 and the valve rod 74 moves in a direction to compress the spring 79. Thereby, as shown in FIG. 1, the state where the first exhaust valve 72 opens the striking cylinder exhaust port 23 and the second exhaust valve 73 opens the combustion chamber exhaust port 32 is maintained.

<Examples of effects of the nailing machine of the present embodiment>
In the nail driver 1A of the present embodiment, compressed air and fuel are supplied to the combustion chamber 3 and a high-pressure gas is generated by burning the mixed gas, and the piston 21 of the striking cylinder 2 is pushed with this high-pressure gas. Thereby, the force which pushes a fastener with the piston 21 and the driver 20 becomes strong.

  Thereby, compared with the conventional gas combustion type nail driver using normal-pressure gas, the output for driving a fastener can be raised.

  In addition, by providing the head valve 4 that opens and closes the blow cylinder inlet 51 between the combustion chamber 3 and the blow cylinder 2, the blow cylinder 2 is not operated only by supplying compressed air to the combustion chamber 3. be able to. Further, by operating the head valve 4 with the combustion pressure of the mixed gas, a separate power source for driving the head valve 4 is unnecessary. Thereby, the structure of the head valve 4 and its drive mechanism can be simplified, and the size and cost of the apparatus can be reduced.

  Now, in the configuration in which the head valve 4 is operated with the combustion pressure of the mixed gas, the high-temperature and high-pressure gas flows from the combustion chamber 3 through the striking cylinder inlet 51 and into the striking cylinder 2, so that the pressure in the combustion chamber 3 decreases. Then, the striking cylinder inlet 51 is closed by the head valve 4. For this reason, the gas in the striking cylinder 2 cannot be exhausted from the combustion chamber 3 to the outside by the operation of the piston 21 returning from the bottom dead center position to the top dead center position.

  Therefore, a blow cylinder exhaust port 23 for communicating the blow cylinder 2 with the outside, and a first exhaust valve 72 for opening and closing the blow cylinder exhaust port 23 are provided. The striking cylinder exhaust port 23 is provided to face the top dead center position of the piston 21.

  Thereby, even if the blow cylinder inlet 51 is closed by the head valve 4 and the gap between the blow cylinder 2 and the combustion chamber 3 is shut off, the piston 21 returns to the top dead center position from the bottom dead center position. The gas in the cylinder 2 can be exhausted from the impact cylinder exhaust port 23 to the outside. Therefore, the piston 21 can be reliably returned to the top dead center position.

  The combustion chamber 3 is provided with a combustion chamber exhaust port 32 that communicates with the outside and a second exhaust valve 73 that opens and closes the combustion chamber exhaust port 32, so that the combustion chamber 3 is operated after the piston 21 of the striking cylinder 2 is operated. The gas remaining inside can be exhausted to the outside.

  Further, the exhaust valve 7 is connected to a first exhaust valve 72 that opens and closes the blow cylinder exhaust port 23 and a second exhaust valve 73 that opens and closes the combustion chamber exhaust port 32 provided in the combustion chamber 3, thereby At this timing, the blow cylinder exhaust port 23 and the combustion chamber exhaust port 32 can be opened. In this example, when the first exhaust valve 72 and the second exhaust valve 73 are integrally connected by the valve rod 74, the timing at which the first exhaust valve 72 and the second exhaust valve 73 are operated. The striking cylinder exhaust port 23 and the combustion chamber exhaust port 32 can be opened without delay.

  Further, the exhaust valve 7 is provided on one side of the striking cylinder 2 with respect to the extending direction of the handle portion 11. Thereby, compared with the structure which provides the exhaust valve 7 between the impact cylinder 2 and the handle part 11 which are the back side of the impact cylinder 2, the distance of the impact cylinder 2 and the handle part 11 can be shortened. Accordingly, the operability is improved by shortening the distance L1 between the driver center P1 of the striking cylinder 2 and the operation position P2 of the operation trigger 16. Further, the distance L2 between the front surface P3 of the main body portion 10 and the driver center P1 of the striking cylinder 2 can be shortened compared with the configuration in which the exhaust valve 7 is provided on the front side of the striking cylinder 2, and it is narrow, such as near the wall surface. It becomes possible to drive into a place, and cornering performance is improved.

  In the present embodiment, the exhaust valve 7 that opens and closes the striking cylinder exhaust port 23 and the combustion chamber exhaust port 32 operates with the gas supplied to the blowback chamber 6. On the other hand, the drive source of the exhaust valve 7 is not limited to the operation by gas. In the present embodiment, air is used as the oxidant, and the compressed oxidant is operated with a mixed gas of compressed air and fuel. However, if oxygen necessary for fuel combustion is included, compression is performed. Not only air but other oxidizing agents may be used. For example, oxygen, ozone, nitric oxide or the like may be used instead of air.

  DESCRIPTION OF SYMBOLS 1A ... Nailing machine, 10 ... Main-body part, 11 ... Handle part, 12 ... Nose part, 13 ... Tank attaching part, 14 ... Magazine, 15 ... Air plug, 16 ... Operation trigger, 17 ... Battery, 18 ... Battery mounting part, 2 ... Blow cylinder (blow mechanism), 2a ... Piston position restricting part, 20 ... Driver, 21 ... Piston, 21a ... piston ring, 22 ... cushioning material, 23 ... striking cylinder exhaust port (exhaust port), 23a ... outer opening, 23b ... inner opening, 24 ... spring receiving part 25a ... Piston lower chamber (one chamber), 25b ... Piston upper chamber, 3 ... Combustion chamber, 30 ... Head, 31 ... Ignition device, 32 ... Combustion chamber exhaust Mouth (exhaust port), 32a ... outer opening, 32b ... inner opening, 4 ... Valve (valve element), 40 ... valve surface, 41 ... first seal part, 41a ... first seal material, 42 ... second seal part, 42a ... second Sealing material, 43 ... working surface, 44 ... spring, 45 ... recess, 5 ... valve support, 50 ... partition, 51 ... impact cylinder inlet, 52 ... Working space, 53... Head valve inlet, 54... Cushioning material, 6... Blowback chamber, 60 .. inflow / outlet, 7 .. exhaust valve (exhaust valve), 71. Exhaust piston, 72 ... first exhaust valve (blow cylinder exhaust valve), 72a ... sealing part, 72b ... sealing part, 72c ... flow path forming part, 73 ... second Exhaust valve (combustion chamber exhaust valve), 73a ... sealing member, 74 ... valve rod, 74a ... spring 75 ... exhaust cylinder, 76 ... exhaust flow path forming cylinder, 76a ... wall portion, 77 ... buffer material, 78 ... long hole portion, 79 ... spring, 8, ...・ Contact member, 80 ... spring, 81 ... link

Claims (9)

A striking cylinder having a piston that operates with a combustion pressure of a gas mixture of compressed oxidant and fuel;
A combustion chamber for burning a gas mixture of compressed oxidant and fuel;
A valve body that opens and closes between the striking cylinder and the combustion chamber;
A hammering tool comprising a hammering cylinder exhaust valve that opens and closes between the hammering cylinder and the outside. The driving tool according to claim 1, further comprising a combustion chamber exhaust valve that opens and closes between the combustion chamber and the outside. The driving tool according to claim 2, wherein opening and closing of the blow cylinder exhaust valve and opening and closing of the combustion chamber exhaust valve are interlocked. The driving tool according to claim 3, wherein the striking cylinder exhaust valve and the combustion chamber exhaust valve are integrated. A main body having the striking cylinder and the combustion chamber;
A handle portion extending from the body portion;
The driving tool according to any one of claims 1 to 4, wherein the blow cylinder exhaust valve is provided on one side of the blow cylinder with respect to a direction in which the handle portion extends. The driving tool according to claim 5, wherein the striking cylinder exhaust valve is operated by movement along an axial direction of the striking cylinder. A main body having the striking cylinder and the combustion chamber;
A handle portion extending from the body portion;
The striking cylinder exhaust valve is provided on one side of the striking cylinder with respect to the extending direction of the handle portion, and the combustion chamber exhaust valve is disposed on one side of the combustion chamber with respect to the extending direction of the handle portion. The driving tool according to any one of claims 2 to 4, wherein the driving tool is provided. The driving tool according to claim 7, wherein the striking cylinder exhaust valve and the combustion chamber exhaust valve are operated by movement along an axial direction of the striking cylinder. The hammering tool according to any one of claims 1 to 8, wherein the hammering cylinder exhaust valve includes a hammering cylinder exhaust port that allows the outside and the inside of the hammering cylinder to communicate with each other at a top dead center position of the piston.

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