JPH085028Y2 - Hydraulic tool with built-in bite release mechanism - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a hydraulic tool used for end treatment work of electric wires, etc., and particularly when a so-called biting phenomenon occurs, the biting can be released. The present invention relates to a hydraulic tool having a release mechanism built-in.

[Conventional technology]

Conventionally, as hydraulic tools, those shown in FIGS. 8 and 9 have been known. That is, the body 52 of the hydraulic tool 51
Is equipped with an oil tank 53 on the right side, a two-stage ram cylinder 54 and two-stage rams (rapid feed ram 55a, high pressure ram 55b) that supply hydraulic pressure to the approximate center of the body 52, and a piston on the left side of the body 52. A cylinder part 57 containing 56 is provided. A fixed head 58 integrally fixed to the body 52 is attached to the tip (left side) of the tool. Further, a tubular grip and handle 59 is attached to the body 52, and the oil tank 53 is internally housed in the handle 59.

In the two-stage rams 55a and 55b, the upper first stage is a low-speed ram 55a for rapid feed, and the lower second stage is a high-pressure ram 55b. The pressure handle 60 is swingably attached to the two-stage rams 55a and 55b, and the pump action of the two-stage rams 55a and 55b due to the next swing of the pressure handle 60 causes the pressure in the oil tank 53 to rise. Oil is sucked into the ram cylinder 54 and discharged to the cylinder part 57, and the piston 56 is the piston return spring.
It will rise against 61.

That is, when the piston 56 rises, the oil flow through the ram 55a for rapid feed is the oil filter 62 and the first oil passage (a) 6
3, the suction valve 64, the first chamber (b) 65, the ram cylinder 54a, the first oil passage (c) 66, the check valve 67, and the third chamber (a) (cylinder portion) 57 flow in this order. The oil flow through the high-pressure ram 55b similarly passes through the oil filter 62 and the first oil passage (a) 63, but is branched thereafter to the intake valve 68, the second chamber (a) 69, the ram cylinder 54b, The check valve 70 and the third chamber (a) (cylinder portion) 57 flow in this order.

As a result, the male die (movable head) 71 fixed to the head of the piston 56 slides together with the piston 56, and moves in the direction of the female die 72 provided on the fixed head 58 to perform a desired terminal treatment operation. Like

When the piston 56 descends, use the pressure handle 60 and return valve 73.
When is pressed, the ball 74 is pushed, and the third chamber (a) (cylinder part) 57, the fifth oil passage (a) 75, the fifth chamber (b) 76, the fifth chamber (c) 77, the fifth chamber Returning to the oil tank 53 through the oil passage (d) 78, the piston 56 is pushed by the piston return spring 61 and descends.

[Problems to be solved by the device]

When performing terminal treatment of electric wires using the above conventional tools,
For example, when the electric wire is cut using a hydraulic cutter, the cutting object such as the electric wire and the blade of the cutter bite each other, and there is often a phenomenon that the piston return spring 61 alone cannot return it, resulting in extremely poor workability. are doing. In order to correct this bite, an impact force is applied with a wood hammer or the like to deal with it, but there is a risk of damaging the hydraulic tool, and improvement has been demanded.

The present invention has been devised in view of the above points, and even if a biting phenomenon occurs, it is possible to easily and quickly release the bite by applying pressure in the direction opposite to the compression or cutting direction by operating the switching valve. An object of the present invention is to provide a hydraulic tool with a built-in bite release mechanism that eliminates the risk of damaging the hydraulic tool.

[Means for Solving the Problem and Its Action]

In order to solve the above problems, in the present invention, an oil tank (18), a ram (15) for pumping the oil (19) of the oil tank (18) to a cylinder (3), and the cylinder (3). The die (13) attached to the tip end of the die is slid in the closing direction by the pressure oil that is internally fitted to the wire, and the sliding of the closing direction cuts or crimps a wire such as an electric wire, In a hydraulic tool equipped with a piston (7) that slides back by a piston return spring (8) that returns the die (13) to the opening direction after cutting or crimping is completed, the die (13) is drilled in the piston (7). The through hole (9) is provided and has a large diameter hole portion and a small diameter hole portion, and has a stepped shape with a large diameter portion at the tip and a small diameter portion at the other end, and the tip large diameter portion has the through hole (9). ) Is fitted into the large diameter hole portion, and the other end small diameter portion is the small diameter hole of the through hole (9). And a reverse pressure piston (12) provided so that the piston (7) can be pressed and slid in the opening direction by sliding in the through hole (9). ) Between the oil passage hole (10) formed in the center of the other end small diameter portion side, and the other end small diameter portion of the counter pressure piston (12) and the large diameter hole portion of the through hole (9). The reverse pressure pressurizing passage (11) formed and communicating with the oil passage hole (10) and the piston (7) move in the closing direction, and the tip thereof is the oil passage hole of the reverse pressure piston (12). A non-return valve (32), which is held at a position where it communicates with (10) and the oil tank (18) and shuts off communication between the cylinder (3) and the oil tank (18) at its tip when moving in the opening direction. The valve rod (33) for opening the valve is connected in series with the valve rod (33), and when the piston (7) moves in the opening direction, the reverse of The oil passage hole of the piston (12) (10)
When the piston (7) moves in the closing direction, the first valve body (34), which is held at a position that blocks communication with the oil tank (18), and the valve rod (33) are connected in series. The ram chamber of the ram (15) is held at a position where it can communicate with the cylinder (3), and when moving in the opening direction, the oil passage hole (10) of the counter pressure piston (12) is moved from the ram chamber of the ram (15). ) A second valve body (35) to be held in a position where it can be introduced into the oil tank (1) and an axial reciprocating motion of the valve rod (33) cause the oil tank (1
The communication state between the oil passage hole (10) of the counter pressure piston (12) and the oil tank (18) from 8) is changed to the first valve body (34).
And a second valve body (35) for switching the pressure oil fed from the ram chamber of the ram (15) into the oil passage hole (10) of the counterpressure piston (12) (36). ) Is provided, and when the die (13) is slid in the closing direction and a biting phenomenon occurs between the wire (such as the electric wire) and the die (13), the ram is provided by using the switching valve (36). The counter pressure piston (12) is introduced into the oil passage hole (10) from the ram chamber (15), and the piston (7) is moved in the opening direction to cancel the bite phenomenon.

By adopting the above configuration, the pressure can be forcibly applied in the direction opposite to the compression or cutting direction by operating the switching valve, so that the bite can be released.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an overall cross-sectional front view of the hydraulic cutter, FIG. 2 is a cross-sectional view of a piston and a ram portion of the hydraulic cutter, and FIG.
Fig. 4 is a sectional view taken along the line III-III in Fig. 2, and Fig. 4 is IV-IV in Fig. 3.
5 is a sectional front view of the switching valve, FIG. 6 is a hydraulic circuit diagram when the piston is raised, and FIG. 7 is a hydraulic circuit diagram when the forced return is performed.

In this embodiment, as shown in FIG. 1, the bite release mechanism of the present invention is applied to a hydraulic cutter 1. In FIG. 1, a cylinder 2 is integrally formed with a body 2 of a hydraulic cutter 1 at an upper portion (left side in the drawing) of the body 2, and a cylinder head 4 is screwed to a tip portion of the body 3 by means such as screwing. The cylinder 3 is externally fitted in close contact with the end thereof. A fixed head 5 is bolted to the tip of the cylinder head 4, and a head cutter 6 is attached inward of the tip.

A piston 7 integrally formed with a large diameter portion and a small diameter portion is slidably mounted inside the cylinder 3, and a piston return spring 8 has one end abutted against the inner end surface of the cylinder head 4 in the small diameter portion. , The other end is abutted against the large-diameter end of the piston 7, and is fitted on the outside. A groove 7a is formed on the outer circumference of the large diameter portion of the piston 7, and a backup ring and a circle ring for preventing pressure oil from rising are externally fitted. A through hole 9 is formed in the center of the piston 7, and a large diameter portion and a small diameter portion are integrally formed in the through hole 9, and an oil passage hole 10 is provided at the center of the small diameter portion. A back pressure piston 12 having a back pressure pressurizing passage 11 is provided between the end portion of the diameter portion and the middle portion of the through hole 9 by being screwed and fixed to the body 2 side. That is, the counter pressure pressurizing passage
When pressure oil is supplied to 11, the piston 7 is forced to slide toward the body 2. A groove 12a and a groove 7b are formed on the outer circumference of the large-diameter portion of the counterpressure piston 12 and the inner circumference of the large-diameter through hole 9 of the piston 7 in contact with the counterpressure piston 12 to prevent pressure oil from rising. A backup ring and a ○ ring for fitting are fitted respectively.

The tip of the piston 7 extends through the cylinder head 4 and is joined to a movable head, that is, a piston cutter 13, which moves integrally with the piston 7. Then, the electric wire or the like is cut by the piston cutter 13 and the head cutter 6.

On the other hand, in the substantially central portion of the tool body 2, there are shown in FIGS.
As shown in the figure, a two-stage ram cylinder for supplying pressure oil
14 and a two-stage ram (rapid feed ram 15, high-pressure ram 16) inserted in the ram cylinder 14 are provided, and a pressure handle 17 is attached to the upper end of the two-stage rams 15, 16. Then, by vertically swinging the pressure handle 17, the two-stage rams 15, 16 are
Reciprocally slides in the ram cylinder 14 and supplies pressure oil into the cylinder 3 by a pump action. An oil tank 18 is provided on the right side (lower side) of the tool body 2 and oil 19 is stored therein. A hollow grip and handle 20 is attached to the right side of the body 2 in such a manner that the oil tank 18 is built therein.

As shown in FIGS. 1 and 2, a hollow oil passage / valve chamber 21 is bored on the right side of the two-stage ram cylinder 14 substantially in the center of the tool body 2, and one end of the hollow oil passage / valve chamber 21 is screwed into a plug 22. Is tightly plugged by. A return valve 25 including a spring 23 and a ball 24 is built in the valve chamber 21. On the other end of the valve chamber 21, there is a pressing pin 27 that opens the ball of the return valve 25 against the elastic force of the spring 26 wound around the tip of the return valve 25 by pressing it with a pressure handle 17. It is movably fitted.

A hollow oil passage / first valve chamber / second valve chamber 28 is bored on the left side of the two-stage ram cylinder 14 substantially at the center of the tool body 2, as shown in FIGS. 1, 5, and 6. The plug 29 is plugged at one end. First valve chamber 28
Is a check valve 32 in which a ball 31 is pressed to the second valve chamber side by a spring 30 whose one end is in contact with the plug 29 side end.
Is provided. A valve rod 33 having a tip facing the ball 31 of the check valve 32 is provided in the second valve chamber, and a first valve element 34 and a second valve element 35 are integrated from the top in the middle of the valve rod 33. The switching valve 36 is formed as a unit. The other end of the valve rod 33 is extended to the outside of the body 2 from a plug 37 screwed into the end of the second valve chamber, and a handle 38 is provided at the end. Then, when the handle 38 is turned in the screw direction, the valve rod
33 can be extruded into the body.

When the piston 7 rises, the switching valve 36 holds the tip of the valve rod 33 at a position where it can communicate with the oil tank 18 from the oil passage hole 10 of the counterpressure piston 12, and the second valve body 35 from the high pressure ram 16 to the cylinder 3 It is held at the position where it communicates with. And
At the time of forced return to release the bite, etc., the handle 38 is turned to push out the valve rod 33, so that the check valve 32 is opened at the tip of the valve rod 33 so that the cylinder 3 can communicate with the oil tank 18. The valve body 34 is placed at a position where the passage from the oil passage hole 10 of the back pressure piston 12 to the oil tank 18 can be blocked, and the second valve body 35 is introduced from the high pressure ram 16 into the oil passage hole 10 of the back pressure piston 12. Set to a position where you can.

According to this structure, when cutting a wire such as an electric wire with the hydraulic cutter, even if biting occurs, the handle 38 of the switching valve 36 is operated to push up the valve rod 33, whereby the back pressure piston 12 Pressure oil can be introduced into the counter pressure pressurizing passage 11 through the oil passage hole 10, and pressure can be forcibly applied to the piston 7 in the direction opposite to the cutting direction to release the bite.

Next, the flow of pressure oil in the hydraulic cutter of the present invention will be described in detail with reference to the hydraulic circuit diagrams (Figs. 6 and 7).

a. When the piston is raised First, the rapid feed ram 15 will be described. By operating the pressurizing handle 17 to move the ram 15, the flow of pressure oil is introduced into the first oil passage (a) 102 through the oil filter 101 of the oil tank 18, and the first through the suction valve 103. Room (b)
104, enters the large-diameter ram chamber of the ram 15 from the outlet of the first chamber (b) 104, is pressure-fed, and passes through the first oil passage (c) 105 to open the check valve 106 to open the cylinder [ The third chamber (a)] 3 is introduced. When the pressure in the cylinder 3 exceeds a set value, the pressure oil sent from the ram 15 opens the low pressure regulating valve 107 and is returned to the oil tank 18.

Next, the high pressure ram 16 will be described. Similarly, the flow of the pressure oil is introduced into the first oil passage (a) 102 via the oil filter 101 of the oil tank 18, passes through the suction valve 108, and flows into the second chamber (a) 109. The oil introduced into the second chamber (a) 109 enters the small-diameter ram chamber of the ram 16, opens the check valve 110, is pressure-fed to the switching valve 36 via the second oil passage (b) 111, and the second valve Body 35
It is sent to the cylinder [third chamber (a)] 3 through the second oil passage (e) 112 opened by.

The flow of the residual oil in the counter pressure piston 12 flows through the counter pressure pressurizing passage [fourth chamber (a)] 11, the oil passage hole [fourth chamber (b)] 10, and the fourth passage (c) 113. Through the gap between the check valve 32 and the ball 31 of the check valve 32, and the fourth passage (d) 11
It flows to 4 and is returned to the oil tank 18.

b. In the case of piston lowering When the piston lowering is by the piston return spring 8, it is almost the same as in the prior art. That is, when the return valve 25 is pushed down by the pressurizing handle 17, the ball 24 of the valve 25 opens as shown in FIG. 2, and the cylinder [FIG. 3 (a)] 3 to the fifth oil passage (a) 115, An oil tank 18 passing through an oil passage and valve chamber [fifth chamber (b), fifth chamber (c)] 21, a fifth oil passage (d) 116.
The piston 7 is lowered by being pushed by the piston return spring 8.

c. In case of forced return If the piston 7 does not return due to bite while rising, rotate the handle 38 of the switching valve 36 to push up the valve rod 33 and operate the pressurizing handle 17 to move the rams 15 and 16. As a result, the pressure oil flows and the forced return is performed as follows. That is, oil flows from the oil tank 18 to the first oil passage (a) 10
2, suction valve 108, second chamber (a) 109, ram 16, check valve 110, second
Oil passage (b) 111, switching valve 36 (passage opened by pushing up second valve body 35), fourth oil passage (d) 117, oil passage hole [fourth passage (b)] 10, reverse pressure The pressurizing passage [fourth chamber (a)] 1 is entered, and pressure in the opposite direction is applied to the piston 7, and the piston 7 is pulled down. Oil remaining in the cylinder [third chamber (a)] 3 is the third
The passage (b) 118, the switching valve 36 (flowing from the gap of the check valve 32 opened by the tip of the valve rod 33) and the fourth oil passage (d) 114 are returned to the oil tank 18 in this order. The oil sent to the large-diameter ram chamber of the ram 15 is sent to the cylinder [third chamber (a)] 3 from the first oil passage (c) 105. It is returned to the oil tank 18 via the valve 36 and the fourth oil passage (d) 114.

Although the embodiment of the present invention shows a piston type hydraulic cutter, it is needless to say that the present invention can be applied to a hydraulic compression tool as in the case of the embodiment. Further, although not described in the present embodiment, when it is necessary to regulate the internal pressure in the cylinder 3, a relief valve for regulating the internal pressure can be incorporated.
Further, when a fast-forwarding device is not required, a straight ram may be used, and the handle 38 of the switching valve 36 may have a lever structure.

[Effect of device]

As described above, according to the hydraulic tool with a built-in bite release mechanism of the present invention, the pressure can be forcibly applied in the direction opposite to the compression or cutting direction by operating the switching valve, so that the bite can be released easily. And it can be done in a short time, and the workability is improved. Further, unlike the conventional case, the operation of hitting with a wood hammer or the like is not required even if there is a bite, so that there is no fear of damaging the hydraulic tool.

[Brief description of drawings]

FIG. 1 is an overall sectional front view of the hydraulic cutter, FIG. 2 is a sectional view of a piston and a ram portion of the hydraulic cutter, FIG. 3 is a sectional view taken along line III-III of FIG. 2, and FIG. Fig. 3 is a sectional view taken along the line IV-IV, Fig. 5 is a sectional front view of the switching valve, Fig. 6 is a hydraulic circuit diagram when the piston is raised, Fig. 7 is a hydraulic circuit diagram at the time of forced return, and Fig. 8 is FIG. 9 is a sectional view of a main part of a conventional hydraulic cutter, and FIG. 9 is a sectional view taken along line IX-IX in FIG. 1 …… hydraulic cutter, 2 …… body 3 …… cylinder, 7 …… piston 8 …… piston return spring 10 …… oil passage hole, 11 …… reverse pressure pressurizing passage 12 …… reverse pressure piston, 15 …… Rapid feed ram 16 …… High pressure ram, 17 …… Pressure handle 18 …… Oil tank, 25 …… Return valve 32 …… Check valve, 33 …… Valve rod 34 …… First valve disc, 35 …… Second Valve body 36 …… Switching valve, 37 …… Plug 38 …… Handle

Claims (1)

[Scope of utility model registration request] 1. An oil tank (18), a ram (15) for sending oil (19) from the oil tank (18) to a cylinder (3), and a ram (15) fitted inside the cylinder (3) and sent under pressure. The die (13) attached to the tip by pressure oil is slid in the closing direction, and the sliding of the closing direction cuts or crimps a wire rod such as an electric wire, and after cutting or crimping the wire rod, A piston (7) that slides back by a piston return spring (8) that returns the die (13) to the opening direction.
A through hole (9) bored in the piston (7) and having a large diameter hole portion and a small diameter hole portion, and a large diameter portion at the tip and a small diameter portion at the other end. It has a stepped shape,
The tip large diameter portion is fitted into the large diameter hole portion of the through hole (9), the other end small diameter portion is fitted into the small diameter hole portion of the through hole (9), and slides in the through hole (9). As a result, a back pressure piston (12) is provided so that the piston (7) can slide under pressure in the opening direction, and an oil bored at the center of the other end small diameter portion side of the back pressure piston (12). An oil passage hole (10) is formed between the passage hole (10), the other end small diameter portion of the counter pressure piston (12) and the large diameter hole portion of the through hole (9).
When the piston (7) moves in the closing direction, the back pressure pressurizing passage (11) communicating with the back pressure pressurizing passage (11) is connected to the oil passage hole (10) of the back pressure piston (12) and the oil tank (18). The cylinder (3) and the oil tank (1
8) A valve rod (33) for opening the check valve (32) for shutting off the communication with 8) and a valve rod (33) connected in series, and when the piston (7) moves in the opening direction, At the tip of the back pressure piston (1
The first valve body (34) for holding the oil passage hole (10) of 2) and the oil tank (18) in a position to block the communication with the valve rod (33) is connected in series to the piston (7). ) Is moved in the closing direction, the ram chamber of the ram (15) and the cylinder (3) are held in a position where they can communicate with each other, and when it is moved in the opening direction, the counter pressure piston is released from the ram chamber of the ram (15). By the axial reciprocating motion of the second valve body (35) and the valve rod (33) which are held in a position where they can be introduced into the oil passage hole (10) of (12), the reverse pressure is applied from the oil tank (18). Oil passage hole (10) of piston (12)
And the communication state with the oil tank (18) is switched using the first valve body (34) and the second valve body (35), and the pressure oil fed from the ram chamber of the ram (15) is reversely compressed. A switching valve (36) that is introduced into the oil passage hole (10) of the piston (12) is provided, and the die (13) is slid in the closing direction so that it is between the wire material such as the electric wire and the die (13). When a biting phenomenon occurs in the piston, the switching valve (36) is used to introduce it from the ram chamber of the ram (15) into the oil passage hole (10) of the counterpressure piston (12), and then the piston (7). A hydraulic tool with a built-in bite release mechanism, characterized in that the bite phenomenon is released by moving the tool in the opening direction.