JPH071224Y2 - Band saw - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to improvement of a band saw machine.

(Prior Art and Problems Thereof) This type of band saw machine includes a vise unit that clamps an object to be cut with a fixed vise jaw and a movable vise jaw, a head that is movable in a perspective manner with respect to the object to be cut, and a shaft for the head. A band saw hung on a pair of worn wheels, and a pair of guide arms provided on the head and sandwiching both ends of the cutting action region of the band saw, after clamping the workpiece by the vise unit, While moving the head close to the object to be cut, a band saw is run to cut the object to be cut,
After the cutting, the movable vise jaw is retracted to release the clamp.However, if the head is accidentally lowered in the unclamped state, the outside of the movable vise jaw is pulled through during clamping. The guide arm that is present may collide with the movable vice jaw.

Therefore, conventionally, in order to prevent such an accident, the movable vise jaw and the main hydraulic cylinder for driving the movable vise jaw are connected via a one-way interlocking mechanism composed of a rack and a ratchet wheel, and when the clamp is released, the rack and the pawl are released. The connection with the car is released to prevent the movable vise jaws from moving backward.

(Problems to be Solved by the Invention) In the above-mentioned conventional band saw machine, a worker has to manually retreat the movable vice jaw, which is troublesome and troublesome.

In view of the above-mentioned conventional problems, the present invention is designed so that, when the clamp is released, the movable vise jaw can be automatically retracted slightly as the first step, and the movable vise jaw can be largely retracted automatically as the second step. The purpose is to provide a band saw.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a head 6 having a band saw 18, a fixed vise jaw 2a and a movable vise jaw 2b of a vise unit 2 provided at a cutting position. A fixed guide for restricting the cutting action region 18a of the saw blade in a direction along the vertical plane, which is supported by the head 6 so as to be movable in the longitudinal direction in a vertical direction with respect to the work A to be clamped by. arm
In the band saw machine, 25 and the movable guide arm 24 are arranged above the fixed vise jaw 2a and the movable vise jaw 2b so as to have a span L which is always wider than the span l of these vise jaws 2a and 2b. The unit 2 fixes the movable vise jaw 2b during forward movement.
2a has a main hydraulic pressure and a cylinder 42 for moving forward and backward for returning, and the forward-side chamber 42a and the returning-side chamber 42b of the main hydraulic cylinder 42 are respectively provided with a hydraulic pressure source 44 or a tank 45. Is connected to the first switching valve 43 selectively connected to the movable vice jaw 2b when the movable vice jaw 2b is moved backward after the clamp is released, in the connection line between the return side chamber 42b and the first switching valve 43. A hydraulic cylinder 46 for limiting the backward movement is provided to limit the backward movement of the jaw 2b to a small movement range from the clamp position to a position slightly before the position directly below the movable guide arm 24. The configuration in which the second switching valve 55 is provided in the detour is adopted.

(Operation) In the above configuration, when the work A is clamped, the hydraulic oil is supplied from the hydraulic pressure source 44 to the forward side chamber 42a of the main hydraulic cylinder 42 via the first switching valve 43, and the movable vice jaw 2b is moved. Moves toward the fixed vise jaw 2a, and the workpiece A is clamped by both vise jaws 2a and 2b.

Next, when the clamp is released, by switching the first switching valve 43, the hydraulic pressure is applied to the reverse movement limiting hydraulic cylinder 46 via the first switching valve 43, and the load causes the reverse movement limiting hydraulic pressure to be applied. A small amount of pressure oil extruded from the cylinder 46 is supplied to the return side chamber 42b of the main hydraulic cylinder 42, and the movable vice jaw 2b can be automatically retracted slightly to release the clamp.

In this unclamped state, even if the head 6 is lowered by mistake, the movable vise jaw 2b is slightly retracted, so the movable guide arm 24 supporting the band saw 18 moves in the same manner as during clamping. There is no risk of passing the outside of 2b and colliding with the movable vice jaw 2b.

When the second switching valve 55 is switched from the clamp release state, a large amount of pressure oil is supplied from the hydraulic pressure source 44 to the return side chamber 42b of the main hydraulic cylinder 42 via the first and second switching valves 43 and 55. As a result, the movable vice jaw 2b can be automatically retracted greatly.

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

1 to 3, reference numeral 1 denotes a machine base, on which a main vise unit 2 for clamping an object A to be cut at a cutting position P and a rear side of the cutting position are provided. The feeding vice unit 3 is provided, and these vice units are
2 and 3 are provided with fixed vice jaws 2a and 3a and movable vice jaws 2b and 3b, respectively. 4 is the upper and lower mounting brackets 5
A head 6 is horizontally supported by the guide post 4 by a guide post that is erected on the machine base 1 via a and 5b. A single-acting hydraulic cylinder 7 for raising the head that is supported is provided.

The head 6 comprises a head main body 8 extending horizontally in the left and right direction and a support pipe body 9 integrally provided so as to vertically penetrate the head main body at a position near one end of the head main body. The tube body 9 is slidably supported on the guide post 4 via a sleeve 10 installed therein, and guide roller pairs 11, 11 provided at two upper and lower positions of one end of the head body 8 are The guide rail 13 extending in the vertical direction on the outer frame portion 12 of the machine base 1 is engageably rotatably engaged with the guide rail 13 sandwiched from both sides, and the cylinder body of the single-acting hydraulic cylinder 7 for raising the head. The lower end of 7a is attached to the machine base 1 and the tip of the piston rod 7b is the support tube 9
Is pivotally attached to the upper end side of the. Therefore, the head body 8
Is moved up and down as the piston rod 7b of the head-moving single-acting hydraulic cylinder 7 moves up and down while being kept in a horizontal position by the guide post 4 and prevented from rotating (deflecting) by the guide rail 13, It is freely accessible to the workpiece A clamped by 2.

A driven wheel 14 for driving a band saw and a drive wheel 15 are axially attached to the head main body 8 by rotary spindles 16 and 17 at both left and right ends thereof, and an endless band saw 18 is hung on both the wheels 14 and 15. However, the wheels 14 and 15 are arranged so that the rotation supporting shafts 16 and 17 are respectively positioned horizontally, and therefore the wheels 14 and 15 are also installed on the rotation supporting shafts 16 and 17. , 15 will be located along the vertical plane. A rotary support shaft 17 of the drive wheel 15 is mounted on a fixed position of the head body 8 and is linked to a drive motor 19 installed on the head body 8. On the other hand, the rotary shaft 16 of the driven wheel 14 is axially supported by a movable bearing member 20, as shown in FIG. 1, and this movable bearing member 20 is fixed to the head main body 8 and is provided with upper and lower guide blocks 21. , 22 are supported so that they can move only in the span direction (distance between supporting shafts 16,17) of both wheels 14,15, and this movable bearing member
A band saw tension adjusting hydraulic cylinder 23 is provided between the head main body 8 and the head body 8 for pushing the driven wheel 14 to push the driven wheel 14 to apply tension to the band saw 18.

As described above, since both wheels 14 and 15 for hanging the band saw are arranged on the head main body 8 so that the rotary support shafts 16 and 17 are located horizontally, the wheels 14 and 15 are hung on both wheels 14 and 15. The upper side and lower side running portions of the band saw 18 to be stretched are located along the horizontal plane. Therefore, in order to regulate the cutting action area 18a set in the lower side running portion of the band saw 18 in the direction along the vertical plane, the lower side running portion of the band saw 18 is movable guides at both ends of the cutting action area 18a. Arm 2
It is twisted at 90 ° with respect to the horizontal plane by 4 and the fixed guide arm 25. The fixed guide arm 25 is bolted to the mounting base 26 of the head 6, and the movable guide arm 24 is horizontally slidably mounted to the mounting base 26.
As shown in FIG. 4, the span L between the two guide arms 24, 25 has a fixed vise jaw 2a and a movable vise jaw.
It is set to be larger than the span l when clamped between 2b and each guide arm when the head 6 is lowered.
24 and 25 pass outside the vice jaws 2a and 2b so as not to collide with the vice jaws 2a and 2b. Reference numeral 40 in FIG. 4 is a space for a guide arm provided outside each vise jaw 2a, 2b, and reference numeral 41 in FIG. 1 is a workpiece detection lever.

FIG. 5 shows a hydraulic control circuit for actuating the main vise unit 2, in which the movable vise jaw 2b moves forward toward the fixed vise jaw 2a during forward movement,
A main hydraulic cylinder that moves backward when returning, a first switching valve 43 that selectively connects the forward-side chamber 42a and the returning-side chamber 42b of the main hydraulic cylinder 42 to a hydraulic pressure source 44 or a tank 45, respectively. Is a reverse movement limiting hydraulic cylinder provided in the connection line between the return-side chamber 42b and the first switching valve 43, and as shown in FIG.
A pressure oil storage chamber 49 partitioned by the piston 48 and a piston drive chamber 50 are formed, and a return spring 51 for urging the piston 48 toward the piston drive chamber 50 side is provided, and further inside the piston 48. Is provided with a check valve 2 which only allows pressure oil to flow from the pressure oil storage chamber 49 into the piston drive chamber 50. Therefore, when pressure oil is supplied from the port 53 into the piston drive chamber 50, the pressure oil causes the piston 48 to move toward the pressure oil reservoir chamber 49 side against the spring 51, whereby the pressure oil in the reservoir chamber 49 is removed. It is adapted to be extruded from the port 54 and supplied into the return side chamber 42b. Reference numeral 55 in FIG. 5 denotes a second switching valve provided in a bypass of the reverse movement limiting hydraulic cylinder 46, which connects the backward movement side chamber 42b and the hydraulic pressure source 44 to the reverse movement limiting hydraulic cylinder 46. It is for connecting without going through.

Next, the procedure for cutting the work A will be described. First, the first switching valve 43 is switched to the (b) position from the state shown in FIG. As a result, pressure oil is supplied from the hydraulic pressure source 44 to the forward side chamber 42a of the main hydraulic cylinder 42 through the first switching valve 43, the movable vice jaw 2b advances, and as shown in FIG. Cut A
Is clamped by the movable vise jaw 2b and the fixed vise jaw 2a. The return side chamber 42 of the main hydraulic cylinder 42
The pressure oil b is passed through the reverse movement restriction hydraulic cylinder 46, the second switching valve 55, and further through the first switching valve 43, and then the tank 45.
Returned to.

Then, the head 6 is lowered by the single-acting hydraulic cylinder 7, and the band saw 18 is run by the wheel drive motor 19 via the wheels 14 and 15 to cut the work A. After the cutting, the head 6 is moved. Raise and return to the original position.

When the clamp is released, the first switching valve 43 is switched to the (C) position. As a result, the piston 48 is moved to the pressure oil storage chamber 49 side by the pressure oil supplied from the hydraulic pressure source 44 to the piston drive chamber 50 of the backward movement limiting hydraulic cylinder 46 through the first switching valve 43, and Pressure oil storage chamber 49 due to movement of piston 48
A small amount of pressure oil extruded from the main hydraulic cylinder 42 is supplied into the return side chamber 42b of the main hydraulic cylinder 42, the movable vice jaw 2b is slightly retracted (about 1 to 5 mm), and the workpiece A is released from the clamp. It

In this unclamped state, even if the head 6 is lowered by mistake, the movable vise jaw 2b is slightly retracted, so the movable guide arm 24 supporting the band saw 18 moves in the same manner as during clamping. There is no risk of passing the outside of 2b and colliding with the movable vice jaw 2b.

Next, if you want to move the movable vice jaw 2b back a lot,
The second switching valve 55 may be switched to the (b) position. As a result, a large amount of pressure oil is supplied from the hydraulic pressure source 44 to the return side chamber 42b of the main hydraulic cylinder 42 through the first and second switching valves 43 and 55, and the rotating vise jaw 2b is automatically retracted largely. Can be made.

(Effects of the Invention) According to the present invention, the clamp is automatically released only by switching the first switching valve from the state in which the workpiece is clamped. Since a small amount of pressure oil is extruded from the cylinder and supplied to the return side chamber of the main hydraulic cylinder, the movable vise jaw is only slightly retracted by the main hydraulic cylinder,
Even if the head is accidentally lowered in the unclamped state, the guide arm that supports the band saw does not pass through the outside of the movable vice jaw and collide with the movable vice jaw as in the case of the clamp.

Further, by simply switching the second switching valve from the unclamped state, the movable vise jaw can be automatically retracted largely, and there is no need for an operator to manually retract the movable vise jaw as in the conventional case. Work efficiency is greatly improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a band saw machine showing an embodiment of the present invention, and FIG.
The figure shows a partially cutaway plan view of the same as above, FIG. 3 is a side view of the same as above, FIG. 4 is a perspective view of the main part of the same as above, FIG. 5 is a hydraulic circuit control diagram of the same as above, and FIG. FIG. 3 is a vertical cross-sectional view of a backward movement limiting hydraulic cylinder used in the above. 2 ... Main vise unit, 2a ... Fixed vise jaw, 2b
...... Movable vice jaw, 6 ... Head, 18 ... Band saw, 2
4,25 …… Guide arm, 42 …… Main hydraulic cylinder, 42a…
… Forward side chamber, 42b …… Forward side chamber, 43 …… First switching valve, 46
...... Reverse movement restriction hydraulic cylinder, 55 …… Second switching valve,
L: guide arm span, l: vice jaw span, A: workpiece.

Claims (1)

[Scope of utility model registration request] 1. A head provided with a band saw is movably supported in a vertical direction with respect to an object to be cut which is clamped by a fixed vise jaw and a movable vise jaw of a vise unit provided at a cutting position, The head is provided with a fixed guide arm and a movable guide arm for restricting the cutting action area of the saw blade in a direction along the vertical plane, above the fixed vise jaw and the movable vise jaw, respectively, and always from the span of the both vise jaws. In a band saw machine having a wide span, the vise unit has a main hydraulic cylinder that moves a movable vise jaw forward toward a fixed vise jaw when moving forward and moves backward when moving backward. Connecting the forward-side chamber and the backward-side chamber of the main hydraulic cylinder to a first switching valve that is selectively connected to a hydraulic pressure source or a tank, respectively. In the connection line between the side chamber and the first switching valve, when the movable vise jaw is moved backward after being unclamped, the backward movement of the movable vise jaw is moved from the clamp position to a position slightly forward of the position directly below the movable guide arm. Up to a small movement range up to, a reverse movement limiting hydraulic cylinder is provided, and a second switching valve is provided in a bypass of the hydraulic cylinder.