Manual hydraulic working device

Abstract

The present invention provides a manual hydraulic working device. The manual hydraulic working device (e.g., a cutting device (10)) comprises: a main body (20); a tool (30) having a working part (e.g., a pair of cutting members (31)); and an operating rod (24) operated by an operator. When the operating rod (24) is operated by the operator, the piston (50) moves, whereby the pressure fluid flows in the fluid path between a plurality of fluid chambers and moves, thereby moving the sliding member (34). The structure is such that when a force resisting the movement of the working part caused by operating the operating rod (24) is applied to the working part, the amount of pressure fluid delivered to one of the plurality of fluid chambers in order to move the sliding member (34) is reduced.

Description

Technical Field

[0001] The present invention relates to a manual hydraulic working device in which an operator operates a tool by operating an operating lever. Background Art

[0002] For example, mobile hydraulic working devices are used to rescue people trapped in cars after a traffic accident or trapped in buildings after an earthquake. Such hydraulic working devices include those disclosed in Japanese Patent Application Publication No. 2002-078988 (JP2002-078988A), in which a top tool such as a cutter or expander is directly attached to a pump unit with a motor that generates pressure fluid; and those disclosed in Japanese Patent Application Publication No. 2005-201285 (JP2005-201285A), in which a top tool and a pump unit with a motor are connected by a hydraulic hose. Furthermore, as mobile hydraulic working devices for rescue purposes, there are also manual hydraulic working devices in which an operator operates the top tool by reciprocating an operating lever several times.

[0003] The following problems exist in manual hydraulic working devices: for example, when using a cutter to cut a round rod such as a steel bar or using an expander to pry open a pair of target components, a large force will be applied to the top tool, and the pressure of the pressure fluid supplied to the top tool will also increase. Therefore, the force required for the operator to operate the operating lever becomes very large, which becomes a large burden on the operator. Summary of the Invention

[0004] The present invention has been made in consideration of such a point, and its object is to provide a manual hydraulic working device in which, when a force resisting the movement of a working part by operating an operating lever is applied to the working part, the force required by the operator to move the operating lever is reduced, thereby reducing the burden on the operator.

[0005] The manual hydraulic working device of the present invention is characterized in that the manual hydraulic working device comprises:

[0006] Main body;

[0007] A tool having a working portion;

[0008] an operating lever, which is operated by an operator;

[0009] a piston disposed on the operating rod;

[0010] a sliding member for moving the working portion, the sliding member being capable of reciprocating movement;

[0011] a plurality of fluid chambers; and

[0012] a fluid path for circulating the pressure fluid moving between the plurality of fluid chambers;

[0013] The manual hydraulic working device has the following structure:

[0014] When an operator operates the operating lever, the piston reciprocates, thereby causing the pressure fluid to flow through the fluid path between the plurality of fluid chambers and move, thereby moving the sliding member and thus moving the working part.

[0015] When a force resisting movement of the operating portion caused by operating the operating lever is applied to the operating portion, the amount of the pressure fluid supplied to one of the plurality of fluid chambers to move the sliding member is reduced.

[0016] According to the manual hydraulic working device of the present invention, when a force resisting movement of the working part by operating the operating lever is applied to the working part, the force required by the operator to move the operating lever is reduced, thereby reducing the burden on the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a front view which shows the cutting device which concerns on embodiment of this invention.

[0018] Figure 2 It means a pair of cutting members from Figure 1 The state shown is a front view of the closed state.

[0019] Figure 3 It roughly indicates Figure 1 The schematic diagram of the internal structure of the cutting device shown is shown.

[0020] Figure 4 It means that Figure 1 The diagram schematically illustrates the state of pressure fluid inside the cutting device when a pair of cutting members of the cutting device are closed from an open state and the operating lever is located at a first position.

[0021] Figure 5 yes Figure 4 The internal structure of the cutting device shown is a cross-sectional view viewed along the arrow AA.

[0022] Figure 6 This is a schematic structural diagram showing the state of the pressure fluid inside the cutting device when the operating lever moves from the first position to the second position.

[0023] Figure 7 yes Figure 6 The internal structure of the cutting device shown is a cross-sectional view taken along arrow BB.

[0024] Figure 8 It means in Figure 1 Schematic diagram showing the state of the pressure fluid inside the cutting device when a pair of cutting members come into contact with a round bar such as a steel bar in the cutting device shown in FIG.

[0025] Figure 9 yes Figure 8 The internal structure of the cutting device shown is a cross-sectional view viewed from the CC direction.

[0026] Figure 10 It means that Figure 1 The diagram schematically illustrates the state of pressure fluid inside the cutting device when a pair of cutting members of the cutting device are opened from a closed state and the operating lever is located at a first position.

[0027] Figure 11 It means that Figure 1 The diagram schematically illustrates the state of pressure fluid within the cutting device when a pair of cutting members of the cutting device opens from a closed state and contacts an opposing member. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The cutting device (hydraulic working device) of this embodiment is used for rescue and the like, and can cut round bars such as steel bars or pry open target members using a cutting portion. Figures 1 to 11 : is a diagram showing a cutting device according to this embodiment. Figures 3 to 11 In the figure, hatching for indicating cross sections at locations around the pressure fluid and return fluid channels is omitted to make the channels for the pressure fluid and return fluid easier to see.

[0029] The cutting device 10 of this embodiment is a device in which an operator can Figure 1 The tool 30 is operated by reciprocating between the first position indicated by the solid line and the second position indicated by the double-dashed line. Specifically, the tool 30 has a pair of cutting members 31 rotating around the shaft 32. When the operator moves the operating lever 24 to the position indicated by the double-dashed line, the tool 30 is operated. Figure 1 By repeatedly moving back and forth between the first position indicated by the solid line and the second position indicated by the double-dashed line, the pair of cutting members 31 will rotate in opposite directions about the axis 32, thereby opening or closing the pair of cutting members 31. In addition, the cutting device 10 is provided with an operating knob 28 for determining the moving direction of the pair of cutting members 31. By rotating the operating knob 28, the moving direction of the pair of cutting members 31 can be switched from Figure 1 The direction of closing from the open state as shown or from Figure 2In addition, in the cutting device 10 of this embodiment, a pair of cutting members 31 move in the direction of closing from the open state and are connected to the round rod W1 (refer to Figure 4 、 Figure 6 、 Figure 8 ) contact, or the pair of cutting members 31 moves in the direction of opening from the closed state and contacts the counterpart member W2 (refer to Figure 10 、 Figure 11 ) contact, the operator makes the force required to reciprocate the operating rod 24 is reduced. The following details of the structure of such a cutting device 10 will be described.

[0030] like Figures 1 to 3 As shown, the cutting device 10 includes a main body 20, a first handle 22 mounted on the main body 20, an operating rod 24, a rod-shaped second handle 26, an operating knob 28, and a tool 30. When an operator carries the cutting device 10, the operator holds the first handle 22. In addition, the operating rod 24 can be moved about the axis 25. Figure 1 When the operator uses the cutting device 10 to cut a round bar W1 such as a steel bar or to pry open a pair of target members W2, the operator holds the second handle 26 with one hand (for example, the left hand) and reciprocates the operating lever 24 between the first position and the second position multiple times with the other hand (for example, the right hand). Figure 1 The operation knob 28 is rotated between the third and fourth positions within a 90° range in the direction indicated by the arrows. When the operator reciprocates the operating lever 24 between the first and second positions multiple times while the operation knob 28 is in the third position, the pair of cutting members 31 moves in the closing direction from the open state. On the other hand, when the operator rotates the operation knob 28 90° from the third position to the fourth position, the operator reciprocates the operating lever 24 between the first and second positions multiple times, the pair of cutting members 31 moves in the opening direction from the closed state.

[0031] use Figures 1 to 3 The structure of the tool 30 will be described. A pair of cutting members 31 are each centered around the axis 32. Figure 1 The open position shown is the same as Figure 2 In more detail, as shown in FIG. Figure 3 As shown, a hollow rod member 33 and a sliding member 34 for receiving the rod member 33 are provided inside the main body 20. The sliding member 34 can move along the Figure 3Slide in the left and right directions. A shaft 36 is provided at the top end of the sliding member 34, and one end of a pair of connecting members 38 is mounted on the shaft 36. Each connecting member 38 can rotate relative to the sliding member 34 around the shaft 36. In addition, a shaft 40 is provided at the other end of each connecting member 38, and the base end of each cutting member 31 is mounted on each shaft 40. Each cutting member 31 can rotate relative to each connecting member 38 around each shaft 40. According to such a structure, if the sliding member 34 is moved to the left with the rod member 33 accommodated, Figure 3 If the sliding member 34 moves to the left in the middle, the connecting members 38 rotate in the direction of separating from each other around the shaft 36, and the shafts 40 move in the direction of separating from each other. Therefore, the pair of cutting members 31 rotate in the direction of closing from the open state around the shaft 32. On the other hand, if the sliding member 34 moves to the left in the state of accommodating the rod member 33 Figure 3 As the connecting members 38 rotate about the shaft 36 toward each other, the shafts 40 move toward each other, and thus the pair of cutting members 31 rotate about the shaft 32 toward the direction of opening from the closed state.

[0032] Next, use Figure 3 、 Figure 4 The sliding member 34 is moved along Figure 3 The structure of the left and right movement in the operation rod 24 is described. A piston 50 is provided at the root of the operation rod 24. If the operation rod 24 reciprocates between the first position and the second position with the shaft 25 as the center, the piston 50 moves along the Figure 3 、 Figure 4 The piston 50 is composed of a first piston 51 and a second piston 52, which are integrally connected along the vertical direction. Figure 3 、 Figure 4 The operating rod 24 reciprocates in the vertical direction. A cylindrical second piston 52 is provided at the base of the operating rod 24, and a cylindrical first piston 51 is mounted on the end face of the second piston 52 on the side farther from the operating rod 24. Furthermore, the first piston 51 is mounted to the second piston 52 at a position where the axis of the first piston 51 and the axis of the second piston 52 are approximately the same. Furthermore, a first piston chamber 54 is provided below the first piston 51, and a second piston chamber 56 is provided below the second piston 52. Furthermore, the diameter of the first piston 51 is smaller than the diameter of the second piston 52. Therefore, the area of ​​the bottom surface of the first piston 51 (the end surface facing the first piston chamber 54) is smaller than the area of ​​the bottom surface of the second piston 52 (the end surface facing the second piston chamber 56). Furthermore, the volume of the first piston chamber 54 is smaller than the volume of the second piston chamber 56.

[0033] like Figure 3 and Figure 4As shown in FIG. 1 , a first liquid chamber 60, a second liquid chamber 72, and a third liquid chamber 74 are provided inside the main body 20. When the operating rod 24 is reciprocated between the first position and the second position with the axis 25 as the center, the piston 50 moves along the axis 10. Figure 3 The pressure liquid is transported from the first liquid chamber 60 to the second liquid chamber 72 or the third liquid chamber 74, or the pressure liquid is returned from the second liquid chamber 72 or the third liquid chamber 74 to the first liquid chamber 60. Figure 3 and Figure 4 As shown in FIG. 1 , a sliding member 34 is arranged inside the second liquid chamber 72. In addition, a hollow rod member 33 is housed inside the sliding member 34, and the internal space of the rod member 33 is connected to the second liquid chamber 72. In addition, a flange member 35 is attached to the base end of the sliding member 34, and the second liquid chamber 72 and the third liquid chamber 74 are divided by the flange member 35. When the sliding member 34 and the flange member 35 are moved to the Figure 3 、 Figure 4 If the sliding member 34 and the flange member 35 move to the left, the volume of the second liquid chamber 72 decreases and the volume of the third liquid chamber 74 increases. Figure 3 、 Figure 4 When the pair of cutting members 31 are located at Figure 1 、 Figure 3 、 Figure 4 When the pair of cutting members 31 are in the open position shown in FIG. 1 , the volume of the second liquid chamber 72 is the largest and the volume of the third liquid chamber 74 is the smallest. Figure 2 、 Figure 10 In the open position shown, the volume of the second liquid chamber 72 is minimum and the volume of the third liquid chamber 74 is maximum.

[0034] like Figure 4 As shown in FIG. 1 , multiple fluid paths 62, 64, 66, 68, 70, 76, 78, etc. are provided inside the main body 20. The first fluid path 62 delivers pressure fluid from the first fluid chamber 60 to the second piston chamber 56, and the second fluid path 64 delivers pressure fluid from the first fluid chamber 60 to the first piston chamber 54. A check valve is provided between the first fluid chamber 60 and the first fluid path 62 and between the first fluid chamber 60 and the second fluid path 64, respectively, so that the pressure fluid does not return from the first fluid path 62 and the second fluid path 64 to the first fluid chamber 60. In addition, the switching valve 90 described later is located at Figures 4 to 9 When the position shown is set, the pressure liquid sent from the first piston chamber 54 to the second fluid path 64 and the pressure liquid sent from the second piston chamber 56 to the third fluid path 66 merge and are sent to the fourth fluid path 68, and are sent from the fourth fluid path 68 to the third fluid chamber 74 via the sixth fluid path 76. Figures 4 to 9In the position shown, the pressure liquid discharged from the second liquid chamber 72 returns to the first liquid chamber 60 through the fifth liquid path 70.

[0035] On the other hand, the switching valve 90 described later is located Figure 10 and Figure 11 When the position shown is set, the pressure liquid sent from the first piston chamber 54 to the second fluid path 64 and the pressure liquid sent from the second piston chamber 56 to the third fluid path 66 merge and are sent to the seventh fluid path 78, and are sent from the seventh fluid path 78 to the second fluid chamber 72 via the fifth fluid path 70. Figure 10 and Figure 11 In the position shown, the pressure liquid discharged from the third liquid chamber 74 returns to the first liquid chamber 60 through the sixth liquid path 76.

[0036] Next, the structure of the switching valve 90 will be described in detail. The switching valve 90 is composed of a slender cylindrical component mounted on the operating knob 28. When the operating knob 28 is rotated by the operator, the switching valve 90 also rotates. In addition, two through holes 92 and 94 are formed in the switching valve 90, and the directions in which the through holes 92 and 94 extend differ by 90 degrees. In other words, in the cross section of the switching valve 90, the through holes 92 and 94 extend in directions orthogonal to each other. When the operating knob 28 is in the third position as described above, the switching valve 90 is in Figures 4 to 9 In the position shown, the second fluid path 64 and the third fluid path 66 are connected to the fourth fluid path 68 by means of the first through hole 92. In this case, the second fluid path 64, the third fluid path 66 and the seventh fluid path 78 are not connected. On the other hand, when the operation knob 28 is in the fourth position, the switching valve 90 is in Figure 10 and Figure 11 In the position shown, the second and third fluid paths 64, 66 are connected to the seventh fluid path 78 via the second through-hole 94. In this case, the second and third fluid paths 64, 66 are not connected to the fourth fluid path 68. Thus, by rotating the operating knob 28, the fluid chamber to which the pressure fluid is supplied from the first and second piston chambers 54, 56 is switched between the second and third fluid chambers 72, 74.

[0037] Figure 5 yes Figure 4 The internal structure of the cutting device 10 shown is a cross-sectional view based on the AA direction. Figure 5 As shown in FIG. 1 , a pressure relief valve 80 is provided near the second piston 52. A flange 81 facing the second fluid path 64 is mounted on the pressure relief valve 80. A spring member 82 is provided above the flange 81, and the spring member 82 is used to constantly apply pressure to the pressure relief valve 80. Figure 5In addition, a pin member 84 is provided at the top of the pressure relief valve 80. A return fluid path 87 is provided below the pin member 84 for returning the pressure fluid to the first fluid chamber 60. Normally, the spring member 82 always applies pressure to the pressure relief valve 80. Figure 5 The downward pressing force in the pressure relief valve 80 blocks the inlet to the return fluid path 87, preventing the supply of pressurized fluid from the third fluid path 66 to the return fluid path 87. Furthermore, a check valve 86 is provided near the pressure relief valve 80. Normally, the check valve 86 does not block the third fluid path 66. As a result, the pressurized fluid supplied from the first piston chamber 54 to the second fluid path 64 and the pressurized fluid supplied from the second piston chamber 56 to the third fluid path 66 merge and are supplied to the fourth fluid path 68 or the seventh fluid path 78.

[0038] In addition, if Figure 5 As shown in FIG. 1 , a relief valve 88 is provided in the second fluid path 64 below the pressure relief valve 80, and a return fluid path 89 is provided below the relief valve 88 for returning the pressure fluid to the first fluid chamber 60. In addition, a spring member 88a is installed on the relief valve 88, and the spring member 88a always applies pressure to the relief valve 88. Figure 5 Normally, the inlet to the return fluid path 89 is blocked by the relief valve 88, so the pressure fluid does not return to the first fluid chamber 60 from the second fluid path 64 via the return fluid path 89. On the other hand, by applying a large pressure to the relief valve 88, the relief valve 88 is opened to overcome the pushing force generated by the spring member 88a. Figure 5 When the pressure liquid moves downward in the middle, the inlet to the return liquid path 89 is opened, so the pressure liquid returns from the second liquid path 64 to the first liquid chamber 60 via the return liquid path 89 .

[0039] Next, the operation of the cutting device 10 of this embodiment having such a structure will be described. First, the operation of moving the pair of cutting members 31 in the direction of closing from the open state to cut the round bar W1 such as a steel bar between the pair of cutting members 31 will be described.

[0040] First, the operator rotates the operating knob 28 to position the operating knob 28 at the third position. Figure 1 When the pair of cutting members 31 are in the open state as shown, if the operator holds the second handle 26 with one hand (for example, the left hand) and reciprocates the operating rod 24 between the first position and the second position multiple times with the other hand (for example, the right hand), the piston 50 moves along the Figure 3 、 Figure 4 The flange member 35 is moved in the vertical direction, thereby delivering the pressure liquid from the first liquid chamber 60 to the third liquid chamber 74, and the pressure liquid delivered to the third liquid chamber 74 is delivered to the flange member 35. Figure 3 、 Figure 4Thus, the sliding member 34 mounted on the flange member 35 is pushed in the left direction with the rod member 33 accommodated. Figure 3 、 Figure 4 Thus, each connecting member 38 rotates in a direction away from each other about the shaft 36, and each shaft 40 moves in a direction away from each other, so that the pair of cutting members 31 rotates in a direction of closing from the open state about the shaft 32.

[0041] To explain this action in more detail, when the operating lever 24 is moved by the operator from Figure 4 Move to the first position as shown Figure 6 In the second position as shown, the piston 50 moves to Figure 4 、 Figure 6 Thus, as Figure 6 As shown, the pressure liquid in the first liquid chamber 60 is delivered to the second piston chamber 56 via the first liquid path 62, and is also delivered to the first piston chamber 54 via the second liquid path 64. Figure 6 In FIG. 1 , the pressure fluid delivered from the first fluid chamber 60 to the first piston chamber 54 and the second piston chamber 56 is represented by a different representation method (specifically, slashes) from the pressure fluid in the first fluid chamber 60 and the second fluid chamber 72. Next, when the operator moves the operating lever 24 from Figure 6 Return to the second position as shown Figure 4 In the first position as shown, the piston 50 moves to Figure 4 、 Figure 6 However, since a check valve is provided between the first liquid chamber 60 and the first liquid path 62 and between the first liquid chamber 60 and the second liquid path 64, the pressure liquid inside the first piston chamber 54 and the second piston chamber 56 will not return to the first liquid chamber 60. Instead, the pressure liquid is delivered from the first piston chamber 54 to the second liquid path 64 and from the second piston chamber 56 to the third liquid path 66. The pressure liquids delivered to the above-mentioned second liquid path 64 and third liquid path 66 merge and pass through the through hole 92 of the switching valve 90 to be delivered to the fourth liquid path 68. Then, the pressure liquid is delivered from the fourth liquid path 68 to the third liquid chamber 74 via the sixth liquid path 76. In this way, the flange member 35 is delivered to the pressure liquid in the third liquid chamber 74. Figure 3 、 Figure 4 The operator pushes the operating lever 24 in the left direction. Figure 4 The first position shown is Figure 6 The flange member 35 is moved back and forth several times between the second position shown in FIG. Figure 3 、 Figure 4 The pair of cutting members 31 are gradually closed by moving in the left direction.

[0042] And, in Figure 8 When the pair of cutting members 31 come into contact with the round bar W1 such as a steel bar, the sliding member 34 and the flange member 35 are moved to the Figure 8 The leftward movement in the piston requires a larger force. In this case, the pressure of the pressure liquid delivered from the first piston chamber 54 and the second piston chamber 56 to the third liquid chamber 74 becomes larger. That is, the pressure of the pressure liquid in the third liquid chamber 74 is greater than the pressure of the pressure liquid in the first liquid chamber 60 and the second liquid chamber 72. Figure 8 In the example, the pressure liquid with increased pressure is represented by a different representation method (specifically, a white water drop pattern is drawn on a black background) than the pressure liquid with unchanged pressure. Figure 9 In the process, the pressure of the pressure liquid sent from the first piston chamber 54 to the second liquid path 64 also increases, so the pressure liquid is used to overcome the pressing force generated by the spring member 82 and the flange 81 is moved to the Figure 9 The pin member 84 also moves upwards. Figure 9 As a result, the inlet to the return fluid path 87 is opened, and the pressure fluid fed from the second piston chamber 56 to the third fluid path 66 is returned to the first fluid chamber 60 from the third fluid path 66 via the return fluid path 87. In addition, the pressure of the pressure fluid fed from the first piston chamber 54 to the second fluid path 64 increases, causing the one-way valve 86 to be opened by the pressure fluid. Figure 9 The third fluid path 66 is blocked by the one-way valve 86 when the piston 50 is pushed to the left. As a result, the pressure fluid delivered from the second piston chamber 56 to the third fluid path 66 does not merge with the pressure fluid delivered from the first piston chamber 54 to the second fluid path 64. The bottom surface area of ​​the first piston 51 is smaller than the bottom surface area of ​​the second piston 52. Therefore, when the piston 50 moves to Figure 8 When the pressure of the pressure liquid delivered from the first piston chamber 54 to the second fluid path 64 is greater than the pressure of the pressure liquid delivered from the second piston chamber 56 to the third fluid path 66. Figure 9 Meanwhile, the force applied from the right to the left by the pressure fluid in the second fluid path 64 to the check valve 86 becomes stronger, so that the third fluid path 66 can be maintained in a state of being blocked by the check valve 86 .

[0043] Therefore, in Figure 8When the pair of cutting members 31 shown above contacts a round bar W1, such as a steel bar, and the piston 50 reciprocates vertically, the pressure fluid supplied from the first piston chamber 54 to the second fluid path 64 passes through the through-hole 92 of the switching valve 90 and is then supplied to the fourth fluid path 68. From the fourth fluid path 68, the pressure fluid is supplied to the third fluid chamber 74 via the sixth fluid path 76. However, the pressure fluid supplied from the second piston chamber 56 to the third fluid path 66 is not supplied to the third fluid chamber 74 but instead returns to the first fluid chamber 60. Since the volume of the first piston chamber 54 is smaller than that of the second piston chamber 56, the amount of pressure fluid supplied to the third fluid chamber 74 per one vertical reciprocation of the piston 50 is substantially reduced. Consequently, the movement of the sliding member 34 and the flange member 35 is also reduced. Furthermore, the pressure fluid supplied from the second piston chamber 56 to the third fluid path 66 returns to the first fluid chamber 60, while only the pressure fluid supplied from the first piston chamber 54 to the second fluid path 64 is supplied to the third fluid chamber 74. Therefore, the pressure of the pressure fluid is lower than when pressure fluid is supplied from both the first piston chamber 54 and the second piston chamber 56 to the third fluid chamber 74. Consequently, the force required by the operator to return the operating lever 24 from the second position to the first position is reduced, thereby alleviating the operator's burden.

[0044] Furthermore, when the pressure of the pressure liquid sent from the first piston chamber 54 to the third liquid chamber 74 becomes higher, for example, because the round rod W1 in contact with the pair of cutting members 31 is too hard, the pressure of the pressure liquid in the second liquid path 64 also becomes higher, thereby overcoming the pushing force generated by the spring member 88a and causing the pressure liquid to push the relief valve 88 toward the bottom. Figure 9 In this way, a large pressure is applied to the relief valve 88, thereby overcoming the pushing force generated by the spring member 88a and causing the relief valve 88 to move to the bottom. Figure 9 During downward movement in the piston 54, the inlet to the return fluid path 89 is opened, so the pressure fluid returns from the third fluid path 66 to the first fluid chamber 60 via the return fluid path 89. In this case, the pressure fluid in the first piston chamber 54 and the pressure fluid in the second piston chamber 56 all return to the first fluid chamber 60, and no pressure fluid is supplied to the third fluid chamber 74. This prevents the pressure fluid in the third fluid chamber 74 from becoming over-pressurized and causing a malfunction of the shutoff device 10.

[0045] Next, the operation of prying the gap between the pair of target members W2 by the pair of cutting members 31 by moving the pair of cutting members 31 in the direction of opening from the closed state will be described.

[0046] First, the operator rotates the operating knob 28 to position the operating knob 28 at the fourth position. Figure 10When the pair of cutting members 31 are in the closed state, if the operator holds the second handle 26 with one hand (for example, the left hand) and reciprocates the operating rod 24 between the first position and the second position multiple times with the other hand (for example, the right hand), the piston 50 moves along the Figure 10 The flange member 35 is moved in the vertical direction, thereby delivering the pressure liquid from the first liquid chamber 60 to the second liquid chamber 72, so that the pressure liquid delivered to the second liquid chamber 72 moves Figure 10 Thus, the sliding member 34 mounted on the flange member 35 is pushed to the right in the state of accommodating the rod member 33. Figure 10 Thus, each connecting member 38 rotates in a direction approaching each other about the shaft 36, and each shaft 40 moves in a direction approaching each other, so that a pair of cutting members 31 rotates in a direction opening from a closed state about the shaft 32.

[0047] To explain this action in more detail, when the operating lever 24 is moved from the first position to the second position by the operator, the piston 50 moves to the Figure 10 Thus, the pressure liquid in the first liquid chamber 60 is delivered to the second piston chamber 56 via the first liquid path 62, and is also delivered to the first piston chamber 54 via the second liquid path 64. Then, when the operator returns the operating lever 24 from the second position to the first position, the piston 50 moves to the Figure 10 However, check valves are provided between the first liquid chamber 60 and the first liquid path 62 and between the first liquid chamber 60 and the second liquid path 64, respectively. Therefore, the pressure liquid inside the first piston chamber 54 and the second piston chamber 56 will not return to the first liquid chamber 60. Instead, the pressure liquid is delivered from the first piston chamber 54 to the second liquid path 64 and from the second piston chamber 56 to the third liquid path 66. The pressure liquids delivered to the above-mentioned second liquid path 64 and third liquid path 66 merge and pass through the second through hole 94 of the switching valve 90, thereby being delivered to the seventh liquid path 78. Then, the pressure liquid is delivered from the seventh liquid path 78 to the second liquid chamber 72 via the fifth liquid path 70. Figure 10 In FIG. 1 , the pressure liquid delivered from the first piston chamber 54 and the second piston chamber 56 to the second liquid chamber 72 is represented by a different representation method (specifically, slashes) from the pressure liquid stored in the first liquid chamber 60 and the third liquid chamber 74. In this way, the flange member 35 is moved by the pressure liquid delivered to the second liquid chamber 72. Figure 10 The operator moves the operating lever 24 back and forth between the first position and the second position several times, thereby gradually moving the flange member 35 to the right. Figure 10 The pair of cutting members 31 gradually opens as the moving direction moves to the right.

[0048] And, in Figure 11When the pair of cutting members 31 as shown above come into contact with the target member W2, the sliding member 34 and the flange member 35 are moved to the opposite direction. Figure 11 In this case, the pressure of the pressure liquid delivered from the first piston chamber 54 and the second piston chamber 56 to the second liquid chamber 72 becomes greater. That is, the pressure of the pressure liquid in the second liquid chamber 72 is greater than the pressure of the pressure liquid in the first liquid chamber 60 and the third liquid chamber 74. Figure 11 In the figure, the pressure fluid whose pressure has increased is represented by a different method (specifically, a white water drop pattern is drawn on a black background) from the pressure fluid whose pressure has not increased. In this case, the pressure of the pressure fluid sent from the first piston chamber 54 to the second fluid path 64 also increases. Therefore, the internal structure of the cutting device 10 when the pair of cutting members 31 is used to cut the round rod W1 such as a steel bar is shown. Figure 9 Similarly, the pressure fluid supplied from the first piston chamber 54 to the second fluid path 64 overcomes the pressing force generated by the spring member 8 and moves the flange 81 toward the second fluid path 64. Figure 9 The pin member 84 also moves upwards. Figure 9 As a result, the inlet to the return fluid path 87 is opened, and the pressure fluid fed from the second piston chamber 56 to the third fluid path 66 is returned to the first fluid chamber 60 from the third fluid path 66 via the return fluid path 87. In addition, the pressure of the pressure fluid fed from the first piston chamber 54 to the second fluid path 64 increases, causing the one-way valve 86 to be opened by the pressure fluid. Figure 9 The left direction in the middle pushes, so that the 3rd fluid path 66 is blocked by the one-way valve 86. Thus, the pressure liquid sent from the second piston chamber 56 to the 3rd fluid path 66 will not merge with the pressure liquid sent from the first piston chamber 54 to the second fluid path 64.

[0049] Therefore, if Figure 11As shown, when the pair of cutting members 31 are in contact with the mating member W2 and the piston 50 reciprocates in the vertical direction, the pressure fluid supplied from the first piston chamber 54 to the second fluid path 64 passes through the through-hole 92 of the switching valve 90 and is then supplied to the seventh fluid path 78. From the seventh fluid path 78, the pressure fluid is supplied to the second fluid chamber 72 via the fifth fluid path 70. However, the pressure fluid supplied from the second piston chamber 56 to the third fluid path 66 is not supplied to the second fluid chamber 72 but instead returns to the first fluid chamber 60. Since the volume of the first piston chamber 54 is smaller than that of the second piston chamber 56, the amount of pressure fluid supplied to the third fluid chamber 74 per one vertical reciprocating movement of the piston 50 is substantially reduced. Consequently, the movement of the sliding member 34 and the flange member 35 is also reduced. Furthermore, the pressure fluid supplied from the second piston chamber 56 to the third fluid path 66 returns to the first fluid chamber 60, while only the pressure fluid supplied from the first piston chamber 54 to the second fluid path 64 is supplied to the second fluid chamber 72. Therefore, the pressure of the pressure fluid is lower than when pressure fluid is supplied from both the first piston chamber 54 and the second piston chamber 56 to the second fluid chamber 72. Consequently, the force required by the operator to return the operating lever 24 from the second position to the first position is reduced, thereby alleviating the operator's burden.

[0050] Furthermore, when the pressure of the pressure liquid supplied from the first piston chamber 54 to the second liquid chamber 72 becomes greater, for example, because the object member W2 contacted by the pair of cutting members 31 is not pried apart, the pressure of the pressure liquid in the second liquid path 64 also becomes greater, thereby overcoming the pushing force generated by the spring member 88a and causing the pressure liquid to push the relief valve 88 toward the bottom. Figure 9 In this way, by applying a large pressure to the relief valve 88, the relief valve 88 is pushed to the bottom by overcoming the pushing force generated by the spring member 88a. Figure 9 During downward movement in the piston 54, the inlet to the return fluid path 89 is opened, so the pressure fluid returns from the third fluid path 66 to the first fluid chamber 60 via the return fluid path 89. In this case, the pressure fluid in the first piston chamber 54 and the pressure fluid in the second piston chamber 56 all return to the first fluid chamber 60, and no pressure fluid is supplied to the second fluid chamber 72. This prevents the pressure fluid in the second fluid chamber 72 from becoming over-pressurized and causing a malfunction of the shutoff device 10.

[0051] The cutting device 10 of this embodiment, having the above-described structure, is provided with a main body 20; a tool 30 having a working portion (specifically, a cutting member 31); an operating rod 24 operated by an operator; a piston 50 provided on the operating rod 24; a reciprocating sliding member 34 for moving the working portion; a plurality of fluid chambers (specifically, a first fluid chamber 60, a second fluid chamber 72, and a third fluid chamber 74); and fluid paths (specifically, fluid paths 62, 64, 66, 68, 70, 76, and 78) for circulating pressurized fluid between the plurality of fluid chambers. When the operator operates the operating rod 24, the piston 50 reciprocates, causing the pressurized fluid to circulate through the fluid paths between the plurality of fluid chambers, thereby moving the sliding member 34 and, in turn, the working portion. Furthermore, when a force resisting movement of the operating portion (e.g., a round bar W1 such as a steel bar or a target member W2) is applied to the operating portion by operating the operating lever 24, the amount of pressurized fluid supplied to one of the plurality of fluid chambers (specifically, the second fluid chamber 72 or the third fluid chamber 74) to move the sliding member 34 is reduced. This reduces the force required by the operator to move the operating lever 24, thereby alleviating the operator's burden.

[0052] In the cutting device 10 of this embodiment, the piston 50 includes a first piston 51 and a second piston 52. When the operator operates the operating lever 24, the first piston 51 and the second piston 52 move integrally. A first piston chamber 54 is provided near the first piston 51, and a second piston chamber 56 is provided near the second piston 52. Furthermore, when the piston 50 reciprocates, after pressurized liquid is supplied from one of the multiple liquid chambers (specifically, the first liquid chamber 60) to the first piston chamber 54 and the second piston chamber 56, pressurized liquid is then supplied from the first piston chamber 54 and the second piston chamber 56 to another liquid chamber (specifically, the second liquid chamber 72 or the third liquid chamber 74). Furthermore, when a force resisting movement of the operating portion caused by operating the operating lever 24 is applied to the operating portion, the pressure liquid supplied from one of the multiple liquid chambers (specifically, the first liquid chamber 60) to the second piston chamber 56 returns to the original liquid chamber (i.e., the first liquid chamber 60). Thus, in order to move the sliding member 34, pressure liquid is supplied only from the first piston chamber 54 to the second liquid chamber 72 or the third liquid chamber 74, thereby reducing the amount of pressure liquid supplied to the second liquid chamber 72 or the third liquid chamber 74.

[0053] Furthermore, in the cutting device 10 of the present embodiment, the area of ​​the end surface of the first piston 51 facing the first piston chamber 54 is smaller than the area of ​​the end surface of the second piston 52 facing the second piston chamber 56 .

[0054] Furthermore, in the cutting device 10 of this embodiment, a check valve 86 is provided in the fluid path (specifically, the third fluid path 66). When a force resisting movement of the operating portion caused by operation of the operating lever 24 is applied to the operating portion, the pressure fluid supplied from the first piston chamber 54 to another fluid chamber (specifically, the second fluid chamber 72 or the third fluid chamber 74) acts on the check valve 86, thereby blocking the fluid path (specifically, the third fluid path 66) of the pressure fluid from the second piston chamber 56 to the other fluid chamber. Consequently, the pressure fluid is not supplied from the second piston chamber 56 to the second fluid chamber 72 or the third fluid chamber 74.

[0055] Furthermore, the cutting device 10 of this embodiment is provided with a return fluid path 87 for returning pressure fluid from the second piston chamber 56 to the original fluid chamber (specifically, the first fluid chamber 60), and a pressure relief valve 80 is provided to block the inlet to the return fluid path 87. Furthermore, when a force resisting movement of the operating portion caused by operation of the operating lever 24 is applied to the operating portion, pressure fluid supplied from the first piston chamber 54 to another fluid chamber (specifically, the second fluid chamber 72 or the third fluid chamber 74) acts on the pressure relief valve 80, opening the inlet to the return fluid path 87. Thus, the return fluid path 87 allows pressure fluid discharged from the second piston chamber 56 to be returned to the original fluid chamber (specifically, the first fluid chamber 60).

[0056] Furthermore, the cutting device 10 of this embodiment is provided with a separate return fluid path 89 for returning the pressure fluid from the first piston chamber 54 to the original fluid chamber (specifically, the first fluid chamber 60), and a relief valve 88 is provided to block the entrance to the separate return fluid path 89. Furthermore, when a greater force resisting the movement of the operating portion caused by operating the operating lever 24 is applied to the operating portion, the pressure fluid flowing from the first piston chamber 54 to the other fluid chamber (specifically, the second fluid chamber 72 or the third fluid chamber 74) acts on the relief valve 88, thereby also opening the entrance to the separate return fluid path 89. This allows the pressure fluid discharged from the first piston chamber 54 to return to the original fluid chamber (specifically, the first fluid chamber 60) via the separate return fluid path 89, preventing the flow of pressure fluid to the second fluid chamber 72 or the third fluid chamber 74. Therefore, it is possible to prevent the pressure liquid in the second liquid chamber 72 or the third liquid chamber 74 from becoming over-pressured and causing the shutoff device 10 to malfunction.

[0057] In the cutting device 10 of this embodiment, the operating lever 24 is rotatable within a predetermined angular range about the shaft 25. Thus, the operator can move the working portion simply by swinging the operating lever 24 about the shaft 25.

[0058] In the cutting device 10 of this embodiment, the working portion is a pair of cutting members 31, each of which is rotatable within a predetermined angular range about an axis 32. In this case, a round bar W1 such as a steel bar can be cut between the pair of cutting members 31, or a pair of target members W2 can be pried apart.

[0059] Furthermore, the cutting device 10 of this embodiment is provided with a first liquid chamber 60, a second liquid chamber 72, and a third liquid chamber 74, and a flange member 35 is attached to the sliding member 34. Furthermore, the flange member 35 is provided between the second liquid chamber 72 and the third liquid chamber 74. When the operator operates the operating lever 24, the piston 50 moves, thereby supplying pressurized liquid from the first liquid chamber 60 to the second liquid chamber 72 or the third liquid chamber 74, thereby moving the flange member 35. Thus, by switching the liquid chamber to which pressurized liquid is supplied from the first liquid chamber 60 between the second liquid chamber 72 and the third liquid chamber 74, the direction of movement of the working portion can be adjusted.

[0060] Furthermore, the cutting device 10 of this embodiment is provided with a switching valve 90 for switching the liquid chamber to which the pressure liquid is supplied from the first liquid chamber 60 between the second liquid chamber 72 and the third liquid chamber 74, and an operating knob 28 for operating the switching valve 90. In this case, the operator can adjust the moving direction of the working part simply by operating the operating knob 28, thereby providing greater convenience for the operator.

[0061] In addition, the manual hydraulic working device of the present invention is not limited to the above-mentioned embodiment, and various modifications can be added.

[0062] For example, the tool of the manual hydraulic working device of the present invention is not limited to one having a pair of cutting members 31 that rotate about an axis 32. Any tool having a working portion that acts on an object can be used, and various tools other than those having a pair of cutting members 31 can be used. For example, a tool in which a piston member is moved forward and backward relative to a cylindrical member to pry apart a pair of object members can also be used.

[0063] The operating lever is not limited to one that rotates about the shaft 25. As long as the piston 50 can be reciprocated, an operating lever that does not rotate about the shaft 25 but reciprocates linearly may be used as the operating lever.

[0064] Furthermore, the liquid chambers provided inside the main body 20 are not limited to the three liquid chambers consisting of the first liquid chamber 60, the second liquid chamber 72, and the third liquid chamber 74. As a manual hydraulic working device having another structure, a structure in which two liquid chambers are provided inside the main body 20 and pressure liquid is supplied from one liquid chamber to the other liquid chamber during the reciprocating movement of the piston, thereby moving the sliding member in one direction, may also be used.

Claims

1. A manual hydraulic working device, wherein: The manual hydraulic working device has: Main body; A tool having a working portion; An operating lever, which is operated by an operator; A piston, which is arranged on the operating rod; A sliding member, which is used to move the working part, and the sliding member can move back and forth; Multiple fluid chambers; as well as a fluid path for circulating the pressure fluid moving between the plurality of fluid chambers, The manual hydraulic working device has the following structure: When the operator operates the operating lever, the piston reciprocates, whereby the pressure fluid flows and moves between the plurality of fluid chambers in the fluid path, thereby moving the sliding member and thus moving the working part. When a force resisting movement of the operating portion caused by operating the operating lever is applied to the operating portion, the amount of the pressure fluid supplied to one of the plurality of fluid chambers to move the sliding member is reduced. The manual hydraulic working device has the following structure: The piston includes a first piston and a second piston, When the operating lever is operated by an operator, the first piston and the second piston move integrally, a first piston chamber is provided near the first piston, and a second piston chamber is provided near the second piston. When the piston reciprocates, after the pressure liquid is delivered from one of the plurality of liquid chambers to the first piston chamber and the second piston chamber, the pressure liquid is delivered from the first piston chamber and the second piston chamber to another liquid chamber. When a force resisting the movement of the operating part caused by operating the operating lever is applied to the operating part, the pressure fluid supplied from any one of the plurality of fluid chambers to the second piston chamber returns to the original fluid chamber.

2. The manual hydraulic working device according to claim 1, wherein: An area of ​​an end surface of the first piston facing the first piston chamber is smaller than an area of ​​an end surface of the second piston facing the second piston chamber.

3. The manual hydraulic working device according to claim 1, wherein: The manual hydraulic working device has the following structure: A one-way valve is provided in the fluid circuit. When a force resisting the movement of the working part performed by operating the operating lever is applied to the working part, the pressure fluid delivered from the first piston chamber to the other fluid chamber acts on the one-way valve, so that the fluid circuit of the pressure fluid from the second piston chamber to the other fluid chamber is blocked by the one-way valve.

4. The manual hydraulic working device according to claim 3, wherein: The manual hydraulic working device has the following structure: The manual hydraulic working device is provided with a return fluid path for returning the pressure fluid from the second piston chamber to the original fluid chamber, and is provided with a pressure release valve for blocking an inlet to the return fluid path. When a force resisting movement of the working part caused by operating the operating lever is applied to the working part, the pressure fluid sent from the first piston chamber to the other fluid chamber acts on the pressure release valve to open the inlet to the return fluid path.

5. The manual hydraulic working device according to claim 4, wherein: The manual hydraulic working device has the following structure: The manual hydraulic working device is provided with another return fluid path for returning the pressure fluid from the first piston chamber to the original fluid chamber, and is provided with a relief valve for blocking an inlet to the other return fluid path. When a greater force resisting movement of the working part caused by operating the operating lever is applied to the working part, the pressure fluid supplied from the first piston chamber to the other fluid chamber acts on the relief valve, thereby also opening the inlet to the other return fluid path.

6. The manual hydraulic working device according to claim 1, wherein: The operating lever is rotatable around an axis within a predetermined angular range.

7. The manual hydraulic working device according to claim 1, wherein: The working portion is a pair of cutting members, and each of the cutting members is rotatable around an axis within a predetermined angular range.

8. The manual hydraulic working device according to any one of claims 1 to 7, wherein: The liquid chamber includes a first liquid chamber, a second liquid chamber and a third liquid chamber, A flange member is mounted on the sliding member, and the flange member is disposed between the second liquid chamber and the third liquid chamber. When an operator operates the operating lever, the piston moves to send pressure fluid from the first fluid chamber to the second fluid chamber or the third fluid chamber, thereby moving the flange member.

9. The manual hydraulic working device according to claim 8, wherein: The manual hydraulic working device includes a switching valve for switching a fluid chamber to which pressure fluid is fed from the first fluid chamber between the second fluid chamber and the third fluid chamber, and an operating knob for operating the switching valve.

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