JPH0353846Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a safety device for wood processing machines, and more specifically, to a safety device for wood processing machines that immediately stops the operation if a human body comes close to a dangerous part of the wood processing machine. be.

A wood processing machine, such as a saw that cuts wood, has a disk-shaped saw blade that rotates at high speed and is placed on a base, and the wood is pressed against it while cutting, or the wood that is fixed to the base is cut at high speed. The rotating disk-shaped serrations are pressed and moved to cut the wood into desired dimensions. Since the saw blades of such a saw machine rotate at high speed, it is very dangerous to cut or injure the operator's fingers or fingers instantly. Therefore, a frame is usually installed around the saw blade to prevent hands and fingers from touching the saw blade, but if the frame is made too tight, it will interfere with wood processing work, so the protection is incomplete. It is something. In addition, a wire may be stretched over the dangerous area and both ends of the wire may be connected to a limit switch sensor, so that when a finger touches the wire, the limit switch will activate and stop the saw blade drive mechanism, or a wire may be placed at a distance from the dangerous area. Some devices are equipped with an infrared light emitting element and a light receiving element that receives the infrared beam sent from the infrared light emitting element, and stop the sawtooth drive mechanism when the infrared beam is blocked by a finger or the like. However, since these require the limit switch, light-emitting element, and light-receiving element to protrude from the surface of the substrate, etc., if the wood is accidentally brought into contact with the part housing the light-emitting element or the like during work, a failure will occur immediately. In addition, since these protrude from the surface of the base or the like, they can get in the way of work, and there are also problems such as wood blocking the light beam or the saw cutting machine stopping even if it comes into contact with the wire. Furthermore, since the wires are stretched in a straight line and the infrared beams also travel straight, it is not possible to curve the detection area, which places significant restrictions on the installation locations of these detection mechanisms.
This has the disadvantage that the degree of freedom in designing the wood processing machine is reduced.

In order to solve the problems of the above-mentioned conventional products, the present applicant has developed an electrode for detecting the approach of a human body attached to an insulating member near the moving position of the saw, and an approach sensor that emits a detection signal when a human body approaches or contacts the electrode. A patent application filed in 1982 provides a detection device and the operation of the saw is stopped by the detection signal emitted by the proximity detection device.
It has already been proposed as No. 069777 "Unexamined Japanese Patent Publication No. 56-164801".

However, the human body approach detection device may not be able to reliably detect proximity or contact when the worker is wearing gloves, so it may not necessarily be a perfect safety device. There is also.

This invention was devised in view of the above points, and its purpose is to wear gloves when fingers are caught between the wood and the presser member that presses it, which is the most dangerous part. It is an object of the present invention to provide a safety device of this kind that can reliably detect the presence of a saw and stop the operation of the saw even if the user is wearing it.

In order to achieve the purpose of the present invention as described above, the present invention provides a safety device for wood processing machines that detects when a part of the body of a worker comes close to an electric saw blade and stops the operation of the electric saw blade. , a slit provided in the backing plate through which the electric sawtooth is inserted; electrodes for detecting human body approach provided on both sides of the slit; a holding member facing the backing plate and movable into and away from the corresponding plate; a movable piece provided on both side edges of the holding member, which is movable relative to the holding member and also serves as an electrode for detecting human body approach; and a switch that detects movement of the movable piece moved by contact stress; An approach detection device that detects the approach of a human body to which an electrode and a movable piece for detecting human body approach are connected to the input unit; To provide a safety device for a wood processing machine, which has a sawtooth braking means for stopping the operation of the electric sawtooth by a signal from at least one of an output and a signal from a switch caused by movement of a movable piece.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.

Fig. 1 is a perspective view of the vertical saw machine, and Fig. 2 is a side view of the same. This is the part on which the lower edge 3a of a certain wooden board 3 is positioned and placed.In order to easily move the wooden board 3 along the surface plate 2, there are a plurality of rollers 2 on the upper side of the surface plate 2.
a is arranged.

4 is a main pillar erected at the rear edge of the base 1;
The upper end portion 4a is formed to protrude forward.

Reference numeral 5 denotes a backing plate which is arranged at an angle between the base 1 and the upper end 4a of the main pillar 4, and is designed to support the back side of the wooden board 3 placed on the surface plate 2. .
Incidentally, as shown in FIG. 3, a vertically long slit 5a is formed in the center of the plate 5, and a disc-shaped sawtooth 8 can go in and out through this slit 5a. Further, on both sides of the slit of the corresponding plate 5, detection parts 5b and 5c made of an insulating material are formed, and on the surface thereof, an electrode 5 for detecting the proximity of a human body is formed.
d and 5e are attached by adhesive or the like.

Reference numeral 6 denotes a support column arranged at an appropriate distance from the plate 5 between the base 1 and the upper end 4a of the main column 4, and 7 a clamp, which will be described later, arranged on the back of the support column 6. This is a holding member supported on the support column 6 by members 9 and 10, and is made of wood impregnated with an insulator such as oil or paraffin.
As shown in FIG. 3, the center part of the holding member 7 has a
A slit 7a into which a disc-shaped sawtooth 8 is inserted is formed, and vertical grooves 7b and 7c are provided at both corners of the holding member 7. On both sides of the holding member 7, a plurality of movable pieces 7d and 7e made of metal plates and having an L-shaped cross section are arranged in the vertical direction. The movable pieces 7d and 7e have long grooves 7f in the front and back direction.
is provided and is attached to the presser member 7 so as to be slidable in the front-rear direction by a pin 7g inserted into the long groove 7f. As shown in FIG. 4, the movable pieces 7d and 7e are constantly moved in the direction of the backing plate 5 by elastic members such as wave-shaped leaf springs 7h attached to the walls of the grooves 7c and 7b of the holding member 7. Normally, the rear end of the long groove 7f is in contact with the pin 7g. In this embodiment, the movable pieces 7d and 7e also function as electrodes for detecting the proximity of a human body.

A switch 70 is disposed between the movable pieces 7e, 7d and the presser member 7, and is attached to the groove wall surface of the presser member 7, so that the fingers can be held between the movable pieces 7d, 7e and the backing plate 5. , the movable pieces 7d and 7e are plate springs 7h.
It is designed to be activated when it moves rearward relative to the holding member 7 against the force of. Note that the switch 70 may be attached to the movable pieces 7d and 7e.

The clamp members 9 and 10 are rotatably attached to the support column 6 at their intermediate portions, rotatably attached to the presser member 7 at one end, and rotatably attached to the drive rod 11 at the other end. installed.

Reference numeral 12 denotes an air cylinder attached to the support column 6, whose piston rod communicates with the drive rod 11, and by driving the drive rod 11 in the vertical direction, the presser member 7 is moved through the clamp members 9 and 10. Activate it.

Reference numeral 13 denotes a guide post disposed substantially parallel to the back plate 5 at the rear center of the back plate 5, and a support mechanism 14 of the sawtooth 8 is movable in the vertical direction along this guide post 13. Retained.
Note that 14a is a carrier that holds the support mechanism 14, and 14b is an air cylinder that moves the sawtooth 8 in the front and back direction.

15 is a motor that moves the sawtooth support mechanism 14 in the vertical direction along the guide column 13; 16 is a wire that supports the sawtooth support mechanism 14 and is operated by the motor 15; and 17 is attached to the tip of the wire 16. Balance weight, 18 is air cylinder 1
A control box houses a control circuit such as a compressor and a motor 15 for supplying air to 2 and 14b, and a main part of an approach detection mechanism to be described later, 19 and 20 are flexible ducts for sucking out sawdust, 2
1 is a control foot switch; 22 is the abutment plate 5;
This is a dimension setting device that is slidably and fixably mounted on a guide rod 22' attached to the guide rod 22'.

FIG. 5 is a block diagram showing the safety device according to the present invention. In the same figure, 23 is an induction motor that drives the sawtooth 8, and 24 is a rotating shaft 25 that connects the induction motor 23 and the sawtooth 8. an attached brake disk; 26 is a brake pad disposed opposite to the disk 24;
27 is a brake control device, 28 is an electromagnetic contactor, 2
9 is a three-phase commercial power supply, 30 is a proximity detection device, 30a
is the sensitivity adjuster. Note that the movable pieces 7d, 7
The electrodes e are electrically connected to each other, and the electrodes 5
d and 5e are electrically connected to each other. Further, 70 is a switch disposed between the movable pieces 7d, 7e and the holding member 7.

FIG. 6 is a specific circuit diagram of the approach detection device 30. In the same figure, a coil L, a capacitor C ₁ ,
C ₂ and transistor TR ₁ constitute a Colpitts oscillation circuit. Transistor TR ₂ is a switching transistor, transistors TR ₃ and TR ₄
is the transistor that drives relay RY. When the human body is not close to the electrodes 5d, 5e, 7d, and 7e, the oscillation circuit oscillates at a frequency determined by the coil L and the capacitors _C1 and _C2 , and this signal is applied to the transistor _TR2 , Since this is turned on, the transistors TR ₃ and TR ₄ are turned off, and the contact ry of the relay RY is turned off.
When a human body approaches any of the electrodes 5d, 5e, 7d, and 7e, the oscillation circuit stops oscillating, so transistor TR ₂ turns off, and transistors TR ₃ and TR ₄ turn on instead, operating relay RY. and turn on the contact ry. When this contact ry is turned on, a signal is emitted from the approach detection device 30. Note that by adjusting the sensitivity adjuster 30a, the oscillation intensity can be changed, and the distance over which the proximity detection device 30 operates when a human body approaches the electrode of the proximity detection device 30 can be adjusted.

The present embodiment is configured as described above, and its operation will be explained below.

As shown in FIG. 1, the wooden board 3 is slid on the surface plate 2 and passed between the backing plate 5 and the holding member 7, and after bringing the tip into contact with the dimension setting device 22, the foot switch 21 is pressed. do. With this operation, control box 1
The operation sequence mechanism in 8 works to first send air to the air cylinder 12 and move the drive rod 11 in the direction of arrow A.
direction and rotate the clamp members 9 and 10 to press the presser member 7 against the wooden board 3 and securely fix the wooden board 3 on the backing plate 5. When this operation is completed, the sawtooth support mechanism 14 rises to a preset height, and then the sawtooth 8 begins to rotate at high speed.

When the sawtooth 8 reaches a predetermined rotation speed, air is supplied to the air cylinder 14b and the sawtooth 8 moves through the slit 5.
Move inside a in the direction of the wooden board 3 and cut into the wooden board 3.
When the motor 15 starts rotating, the sawtooth support mechanism 14 begins to descend along the guide column 13, so the sawtooth 8 descends along the slits 5a and 7a to cut the wood board 3. When the sawtooth support mechanism 14 is completely lowered and the sawtooth 8 cuts the wooden board 3,
Air is supplied to the air cylinder 14b, and the sawtooth 8 is drawn into the slit 5a and stops rotating. When the sawtooth 8 stops rotating, the air cylinder 1
Air is supplied to the drive rod 2 to move the drive rod 11 in the direction of arrow B, rotate the clamp members 9 and 10, and release the presser member 7 from the wooden board 3, completing one cycle of the operation sequence.

During the above-mentioned operation, in a normal state, that is, when there is no human body near the saw teeth 8 or near the moving path of the saw teeth 8, the approach detection device 30 does not emit any signal. Therefore, when a start signal is applied to the electrode contactor 28 from the terminal S, it is turned on, and the electrode is applied to the induction motor 23, which rotates and the sawtooth 8 rotates. When the start signal applied to the electrode contactor 28 is cut off, the electromagnetic contactor 28 is turned off and the induction motor 23 is stopped.

While the sawtooth 8 is rotating, if a human body touches or approaches the electrodes 5d, 5e for human body approach detection and/or the movable pieces 7d, 7e that also serve as electrodes for human body approach detection, a signal is sent from the approach detection device 30. is emitted. This signal is applied to electrode contactor 28 and brake control 27. Therefore, the electromagnetic contactor 28 is immediately turned off and the supply of power to the induction motor 23 is stopped. Then, the brake control device 27 also operates to control the brake pads 26.
is pressed against the disk 24 to instantly stop the saw teeth 8, and at the same time, the motor 15 is also stopped, and all power supply to the entire apparatus is stopped. At this time, the pressing member 7 releases the pressure on the wooden board 3, returns to the initial state, and the operation of the entire apparatus is completely stopped.
Therefore, when the human body reaches the sawtooth 8, it has already stopped and the human body is safe. Then, when the human body moves away from the electrodes 5d, 5e, 7d, and 7e, the signal from the proximity detection device 30 disappears, and the wood processing machine automatically returns to its original operating state and starts cutting wood.

Note that it may be dangerous if the wood processing machine starts immediately when the human body is removed, so if the wood processing machine has stopped due to the safety device according to the present invention, do not start the wood processing machine immediately. A return switch may be provided, and the wood processing machine may be started only when the return switch is turned on. In this case, operating the return switch and foot switch 21 in this order will start the motor 15.
By operating the foot switch 21, the electromagnetic contactor 28 is turned on, the brake control device 27 is operated, and the sawtooth disk 8 starts rotating again.

Note that by adjusting the sensitivity adjuster 30,
You can freely set the approach distance to the human body at which the safety device operates.

The aforementioned safety devices include electrodes 5d, 5e, 7d, 7e.
It is activated when a human body approaches or touches the electrode, but if the human body's fingers are completely dry or the worker is wearing gloves, even if the human body comes into contact with the electrode,
The proximity detection device may not emit a signal and the safety device may not operate. At this time, according to the present invention, if a person's finger is caught between the movable pieces 7d and 7e attached to the presser member 7 and the wooden board 3, the movable piece 7
d and 7e retreat against the force of the leaf spring 7h, actuating the switch 70 and issuing a signal to the electrode contactor 28 and the brake control device 27. As a result, similarly to the above, the electromagnetic contactor 28 is turned off and the supply of power to the induction motor 23 is stopped, and the brake control device 27 is activated to press the brake pad 26 against the disk 24 and apply pressure to the sawtooth 8. Since it stops instantly, it is possible to prevent injury to the human body.

As described above, according to the present invention, a movable piece that also serves as an electrode for detecting the proximity of a human body is disposed on the holding member that presses the wooden board against the patch plate, which is always urged by an elastic member to move in the direction of the patch plate. At the same time, a switch is provided that is activated when the movable piece moves against the elastic member, and the activation signal from the switch causes the saw to stop operating. Even if a hand is caught between the presser member and the wooden board, the movable piece is moved by the fingers that are caught and operates the switch, so the operation of the saw can be reliably stopped. It can prevent injuries caused by saw teeth on the human body.

In addition, when a bare finger touches or approaches at least one of the human body approach detection electrode or the movable piece that also serves as the electrode, the proximity detection device detects this and ensures that the saw is The operation can be stopped, and injury to the human body caused by saw teeth can be prevented.

Furthermore, since the movable piece of the present invention also serves as an electrode for detecting the proximity of a human body, it has the advantage of reducing the number of parts. Since the saw blades can be narrowly limited to a specific location, the saw blades can be stopped only when necessary, without having to stop the saw blades unnecessarily. This allows the wood processing machine to operate more efficiently than a machine that is equipped with both separately.

Although the present invention has been described above based on the illustrated embodiments, the present invention is not limited to those shown in the embodiments. For example, in the embodiments, the present invention is applied to a vertical saw machine. I have shown what was done, but
It goes without saying that this can be applied to horizontal saws, and can also be applied to woodworking machines other than saws with almost no changes.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the vertical saw machine, Fig. 2 is a side view of the same, Fig. 3 is a partial perspective view showing the state in which the saw blade moves in and out, Fig. 4 is a sectional view taken along the - line in Fig. 3; FIG. 5 is a block diagram showing an embodiment of the safety device according to the present invention, and FIG. 6 is a circuit diagram of the approach detection device. 1...Base, 2...Surface plate, 3...Wood board, 4...
Main pillar, 5... Backing plate, 6... Supporting column, 7... Holding member, 7d, 7e... Movable piece, 7h... Leaf spring,
70... Switch, 8... Sawtooth, 13... Guide post, 14... Sawtooth support mechanism, 23... Induction motor, 24... Disc, 25... Rotating shaft, 26... Brake pad, 27... Brake Control device, 28... electrode contactor, 29... three-phase commercial power supply, 30... proximity detection device.

Claims (1)

[Scope of utility model registration request] A safety device for a wood processing machine that detects when a part of a worker's body comes close to an electric saw blade and stops the operation of the electric saw blade includes a slit 5a provided in a backing plate 5 through which the electric saw blade is inserted; Electrodes 5 for human body approach detection provided on both sides of the slit 5a
d, 5e, and a corresponding plate 5 facing the said backing plate 5.
a presser member 7 that can freely move toward and away from the presser member 7; movable pieces 7d and 7e that are provided on both side edges of the presser member 7 and that are movable relative to the presser member 7 and also serve as electrodes for detecting human body approach; A switch 70 detects the movement of the movable pieces 7d and 7e moved by the
and an approach detection device 30 in which the human body approach detection electrodes 5d, 5e and the movable pieces 7d, 7e are connected to an input section and detect the approach of a human body to these;
The electrodes 5d and 5e for human body approach detection, and the movable piece 7
Approach detection device 30 when a human body approaches d, 7e
and a sawtooth braking means for stopping the operation of the electric sawtooth by a signal from at least one of the output from the switch 70 and the signal from the switch 70 caused by the movement of the movable pieces 7d and 7e.