KR101798748B1 - Pressure overload protection device for the mechanical press - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload prevention device for a press machine that prevents overload in a mechanical press machine.
In the mechanical press machine, excessive pressures exceeding the set pressure are applied due to various causes during press working, resulting in damage of the workpiece as well as damage to the press apparatus. A variety of devices have been developed and used to detect excessive pressure as soon as it occurs and to prevent excessive pressure rise. The overload detecting device is integrally connected to the spool (201) and the touch bar (202), which are lifted and lowered together with the lifting and lowering of the poppet (200). Such an overload sensing device of the external exposure type often causes an operation failure when an actual dangerous overload condition occurs due to contamination of the sensor bolt due to external pollutants during the long period of use and failure of the fastening state.
The present invention includes an inlet port that is hydraulically connected to a press apparatus and receives hydraulic pressure according to a press operation of the press apparatus, a poppet that is operated to move up and down by hydraulic pressure supplied to the inlet port, and a spool that is interlocked with the operation of the poppet Overload prevention pump,
An overload piston for applying a balanced pneumatic pressure to the overload preventing pump so as to balance the hydraulic pressure set in the overload preventing pump for the press device, a signal generating part provided outside the overload piston, A balance pressure regulating unit including an overload cylinder for regulating the pressure of the fuel,
And a controller for setting a setting position of the signal sensing unit. The overload sensing unit includes a signal sensing unit assembled at one side of the outer housing of the balance pressure regulating unit, and an adjusting unit for setting the setting position of the signal sensing unit.
Therefore, the overload detection is built in the inside of the housing. At the same time, since the signal is detected in a non-contact manner, the transmission of the fast signal shortens the stopping time of the press machine and the trouble does not occur even after long use. And the generation of visually recognizable light and, if necessary, sound are also caused to minimize the damage of the apparatus due to excessive hydraulic pressure.

Description

Technical Field [0001] The present invention relates to an overload protection device for a press machine,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload prevention device for protecting a press machine and a mold from damages caused by a pressure higher than an allowable guaranteed pressure in a mechanical press machine.

In the mechanical press apparatus, excessive pressures exceeding the set pressure are applied to the press machine due to various causes, thereby damaging the workpiece, as well as damaging the press machine and the mold. A variety of devices have been developed and used to detect excessive pressure as soon as it occurs and to prevent excessive pressure rise.

As shown in Fig. 1, in the " Overpressure prevention pump for press machine ", the present inventor's Practical Registration No. 20-0472330 discloses an overload preventing pump used in a press machine,

A partition wall 11 for partitioning the left and right sides is formed at an inner center and an auxiliary installation 12 is formed at a central portion and a piston shaft coupling portion 13 is formed at a left side portion of the auxiliary installation 12, A first cover plate engaging portion 14 and an outer case engaging portion 16 are formed on a left side portion of the partition wall 11 and a right side portion of the partition wall 11 is formed on the right side of the partition wall 11, A main case 102 having an inner cover engaging portion 24, an intermediate cover engaging portion 26, and a third diaphragm engaging portion 28 formed thereon;

A shaft hole 32, a connecting block bush connecting portion 34 and a connecting block fitting portion 36 are formed at a central right side portion of the main case 102 and a spring coupling portion 38 is formed at a right side portion thereof. An outer case 104 formed therein;

A flange shaft portion 82 is formed at an intermediate portion and a piston portion 78 is divided into a shaft body 78 and a rear shaft body 80 by the flange shaft portion 82 and a groove portion 84 is formed in the rear shaft body 80, An axis 124;

A bush unit 138 fitted to and joined to the front shaft body 78 and the rear shaft body 80 of the piston shaft 124 so as to linearly move the piston shaft 124;

A sealing ring groove 46 is formed on the outer circumferential surface and a second diaphragm engaging portion 48 is formed on the left side surface of the piston shaft 124 and a flange shaft portion 82 of the piston shaft 124 is coupled A first diaphragm 110;

A shaft hole 54 is formed at the center of the flange shaft portion 82 and is connected to the second diaphragm coupling portion 48 formed on the first diaphragm 110, A second diaphragm 112 having a flange portion 56 formed thereon;

A spring 114 which is located on the left side of the second diaphragm 112 and which is in contact with the right side of the flange portion 56 and is engaged with the spring engagement portion 38 of the outer case 104 to act elastically;

A shaft hole 81 is formed on the left side surface of the main case 102 so as to be connected to the third diaphragm coupling part 28 and an outer cover engaging part 97 is formed on the left side surface, A third diaphragm 136 having a bushing 77 formed on the left side thereof and coupled to the piston shaft 124;

An outer cover bushing coupling hole 94 is formed at an inner center of the third diaphragm 136 and is coupled to an outer cover coupling portion 97 of the third diaphragm 136, An outer cover 130 on which a coupling tab 96 is formed and a coupling tab 98 is formed on the right side;

An inner cover 132 fitted to the outer side of the inner cover engaging jaw 96 of the outer cover 130 and having an outer cover engaging hole 95 formed at the center thereof;

A contact portion 53 is formed at the upper and middle portions of the center of the inner cover 132 so as to be in contact with the right side surface of the inner cover 132, And an intermediate cover (134) provided so as to be in contact with the press.

In order to adjust the pressure balance between the hydraulic pressure transmitted from the hydraulic press device and the set pressure control pressure, the pressure control poppet is provided with an appropriate pressure and spring tension at a predetermined position, .

If such a balance is not balanced due to various reasons, as shown in FIGS. 2A and 2B, that is, when a situation such as an excessive oil pressure occurs, movement of the external touch signal bar occurs according to this situation, It senses the abnormal pressure from the switch part which generates the ON / OFF signal. When such abnormality is detected, the press machine is suddenly stopped due to an urgent operation stop of the press machine and discharge of pressure against excessive pressure, thereby preventing further damage.

In the conventional overload protection device of the present invention, the spool (201) that ascends and descends together with the lifting and lowering of the poppet (200) is integrally connected to the touch bar (202). A length-adjustable sensor bolt (203) is fastened to the distal end of the touch bar. The sensor bolt has a structure in which the sensor terminal is in contact with and non-contact with the switch terminal (204) for transmitting a signal to the on / off switch box. When an excessive hydraulic pressure is generated due to various causes, an excessive hydraulic pressure is drawn through the inlet port 210 as shown in FIG. 2B, so that the inner poppet rises by the hydraulic pressure and the spool moves together. The movement of the spool moves the touch bar fastened to the spool together so that the sensor bolt at the distal end of the touch bar generates a mechanical contact to the switch terminal or a non-contact situation in the opposite direction, give. When such a signal is generated, various hydraulic control devices and control devices not shown release the excessive hydraulic pressure together with the urgent operation stop of the press device to prevent further damage.

In the mechanical structure described above, since the position where the sensor bolt is fastened is exposed to the outside as shown in the photograph of the photograph of FIG. 5, foreign matter mixed with various dust and oil around the sensor bolt accumulates in the sensor bolt and switch terminal An abnormal contact signal is generated between the sensor bolt and the switch terminal during unexpected use for a long period of time. Even if there is excessive oil pressure, the generation of the signal is delayed due to these foreign substances, which causes a problem of damaging the press device or the die. Another problem is that the operation guide hole 202a must be inevitably installed for the forward and backward movement of the touch bar and various foreign substances ), The internal operation is not smoothly performed. In addition, in the worst case, the operation induction hole is closed and an unexpected serious accident occurs frequently because the abnormal pressure signal is not detected.

An object of the present invention is to provide an overload prevention device that prevents the risk of malfunction due to a foreign object or a change in a fastening position due to long-term use of a sensor bolt and a switch terminal when an overload occurs suddenly.

In order to solve the disadvantages of the mechanical overload detection device, the present invention provides an overload detection device for an overload detection device, comprising: an inlet port that is hydraulically connected to a press apparatus and receives hydraulic pressure according to a press operation of the press apparatus; a poppet that is operated by hydraulic pressure supplied to the inlet port; An overload piston including a spool interlocking with the operation of the poppet, an overload piston for applying a balanced air pressure to the overload prevention pump so as to balance the hydraulic pressure set in the overload prevention pump for the press device, And an overload cylinder for guiding the up and down movement of the overload piston, a signal sensing unit assembled to one side of the outer housing of the balance pressure regulating unit, And an adjusting unit for setting a setting position, An overload prevention device for a press device having a part is developed.

In the present invention, the signal generating unit and the signal sensing unit can accurately detect the occurrence of excessive hydraulic pressure by using a non-contact signal generating and receiving unit such as a magnetic field, light, and ultrasonic waves.

The present invention also induces the generation of light or sound when an abnormal state is detected, enabling direct recognition by an operator.

In the overload detection of the present invention, the signal generating unit and the signal sensing unit are configured to be noncontact with each other. Particularly, since the signal generating unit and the sensing unit are installed in the apparatus, the operation guide hole 202a shown in FIGS. 2A and 2B is sealed by the contamination in the factory which drives the press apparatus which is contaminated with various fine particles and oil. As a result, they are completely free from contamination from these pollutants.

As a result of the isolation from such pollution, the main cause of the malfunction that occurs most frequently due to long-term use disappears, and accurate operation is possible without concern for malfunction due to malfunction, as well as maintenance after repair.

In addition to simple overload protection, signal generation uses various signals such as magnetic field, ultrasonic wave, and light, so it is possible to set the sensitivity of overload detection accurately. Further, the overload control pressure according to the type and shape of the article to be press-molded in the press apparatus can be finely adjusted by adjusting the control member, thereby enabling more accurate and safe overload prevention. Also, since the appropriate position by the control member 312 can be made by a bolt nut assembly that can be arbitrarily adjusted depending on the characteristics of the press apparatus, maintenance and maintenance operations as well as various types of press apparatuses can be performed. It became possible.

1 is a sectional view of an overload preventing pump of the present inventor,
FIGS. 2A and 2B are cross-sectional views illustrating the operation of the overload protection device of the present inventor,
3 is a cross-sectional view of only the overload detection sensor unit in a state in which the overload protection pump of the present invention is installed,
4 is an exploded perspective view of the overload detection sensor unit of the present invention,
FIG. 5 is a photograph showing a state of contamination of a conventional overload detection device. FIG.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

Although the overload device exemplified in the present invention basically exemplifies a press device which mechanically forms by high pressure using a mold, it is also applicable to various devices applying pressure by hydraulic pressure, It belongs to the scope. Pressure press apparatus employing the overload apparatus exemplified in the present invention is not specifically shown, but various applications of the overload apparatus are possible, and the present invention is not limited by these examples.

The overall structure of the present invention is a cross-sectional view in which only the overload detection sensor unit is cut while the conventional overload protection pump is installed in FIG. 3, and FIG. 4 is an exploded perspective view of the overload detection sensor unit.

The present invention relates to a hydraulic control apparatus for an internal combustion engine, which comprises an inlet port (210) hydraulically connected to a press apparatus and adapted to receive hydraulic pressure according to a press operation of the press apparatus, a poppet (200) operated by hydraulic pressure supplied to the inlet port, An overload preventing pump (A) including a spool (201)

An overload piston (301) for applying a balanced air pressure to the overload prevention pump so as to balance the hydraulic pressure set in the overload protection pump for the press device, a signal generator (302) provided outside the overload piston, A balance pressure regulating portion B including an overload cylinder for guiding the upward and downward movement of the piston,

A signal sensing unit 311 installed at one side of the outer housing of the balance pressure regulating unit and an overload detecting unit C configured to set a setting position of the signal sensing unit, And an overload prevention device.
The overload preventing pump has the same structure as that of the conventional overload preventing pump shown in FIGS. 2A and 2B, and a description of these structures is omitted.

The air pressure supply device (high-pressure air compressor), not shown in the present invention, supplies an air pressure of a predetermined pressure to the balance pressure regulator. The supplied air pressure is supplied to the inside of the overload cylinder, and the overload piston pushes the spool under pressure by the hydraulic pressure by the air pressure. The balance between the above-described pressure due to the air pressure and the pressure due to the hydraulic pressure transmitted from the press device applied to the spool is balanced within a predetermined allowable range error in the operation of the normal press device. The allowable range of such a balance is appropriately set and set in accordance with the specification and use of the press device to which the overload device is to be installed.

In the present invention, the overload piston of the balance pressure regulating portion contacts the spool tip of the overload prevention pump. Accordingly, the overload piston is disposed at a predetermined position with a balance between the pressure received by the press apparatus and the air pressure received by the overload piston. When the spool is raised, the overload piston is also raised. When the spool is lowered, the overload piston is also lowered.

The position of the spool and the overload piston is set according to the user's pressing apparatus. When the press apparatus is normally operated in a certain pressure range, the spool is always balanced by the overload prevention pump A.

An overload piston is disposed in the inner liner 316 of the overload cylinder 319 of the balance pressure regulator through a spring device 315 such as a spring, The ring 317 of the overload piston comes in contact with the inner surface of the cylinder liner to prevent outflow of the high pressure air introduced from the cylinder liner to the outside.

A signal generator for generating a magnetic field such as a magnet is provided outside the overload piston. In addition to the magnet, the signal generating part may be an electric field, an ultrasonic wave, or a light. Any signal capable of detecting the moved signal when the position is moved can be employed.

In the present invention, a signal sensing unit is installed on one side of the outer housing of the balanced pressure regulator. The signal sensing unit is installed in an assembler formed at one side of the outer cylinder by an adjusting member. In the simplest manner, the assembling process can be implemented by a fastening structure such as a bolt nut, a fitting type such as a forced fit, and an adhesive bonding method. Such a fastening method can be arbitrarily selected depending on the installation site and conditions of the press apparatus, and there is no particular limitation.

The most characteristic part of the installation of the signal sensing unit of the present invention is that the regulator 312 can be arbitrarily adjusted and installed corresponding to the installation position of the signal generating unit 302 of the overload piston. That is, when there is a large or small change in the operating pressure of the press apparatus and the sensitivity of the overload detection is to be adjusted, the desired overload detection sensitivity can be adjusted only by the simple positional change of the control member.

In the present invention, the signal sensing unit provided at one side of the outer housing of the balance pressure regulating unit is installed in an assembling hole formed at one side of the outer cylinder, and a light transmitting window 318 is installed at one side of the assembling hole Respectively. When the signal sensing unit senses a signal of the signal generating unit, the light emitting window emits light that can be visually recognized from the signal generating unit so that the operator can immediately check the signal.

Another feature of the present invention is that a separate sound generating device 320 is installed in the light transmitting window. That is, when light above a value set in the light emitting window is generated, the light is amplified and an operation signal for a sound generating device, which is not shown, is transmitted, so that even if the user can not visually recognize the current state, .

A: Overload prevention pump, B: Balance pressure control part, C: Overload detection part,
301: overload piston 302: signal generating section 311: signal detecting section 312: regulating section 318: light projecting window 319: overload cylinder

Claims (7)

An inlet port that is hydraulically connected to the press apparatus and receives hydraulic pressure according to the press operation of the press apparatus, a poppet that is operated to move up and down by the hydraulic pressure supplied to the inlet port, and a spool that interlocks with the operation of the poppet, ,
An overload piston for applying a balanced pneumatic pressure to the overload preventing pump so as to balance the hydraulic pressure set in the overload preventing pump for the press device, a signal generating part provided outside the overload piston, A balance pressure regulating unit including an overload cylinder for regulating the pressure of the fuel,
And an overload sensing unit including a signal sensing unit assembled at one side of the outer housing of the balance pressure regulating unit and an adjusting unit setting a setting position of the signal sensing unit.
The method according to claim 1,
Wherein the overload piston of the balance pressure regulating portion is disposed so as to be in contact with the spool tip of the overload prevention pump and to interlock with the spool.
The method according to claim 1,
An overload piston is disposed in the inner liner of the overload cylinder of the balance pressure regulating portion via a collision device,
And the ring of the overload piston contacts the inner liner of the overload cylinder to move up and down in the overload cylinder.
The method according to claim 1,
Wherein the signal generating unit of the balance pressure regulating unit is any one of a magnet for generating a magnetic field, an ultrasonic generator for generating ultrasonic waves, and a light generator for generating light.
The method according to claim 1,
The signal sensing part assembled at one side of the outer housing of the balance pressure regulating part is installed by an adjusting part of an assembler formed at one side of the outer cylinder,
Wherein the regulator is adjustably installed in correspondence to a mounting position of the signal generating part of the overload piston.
The method according to claim 1,
The signal sensing part assembled at one side of the outer housing of the balance pressure regulating part is installed by an adjusting part of an assembler formed at one side of the outer cylinder,
A light projecting window is provided on one side of the assembling hole,
Wherein the light transmitting window is configured to be visually distinguishable by transmitting light generated in the signal detecting unit.
The method according to claim 1,
The signal sensing part assembled at one side of the outer housing of the balance pressure regulating part is installed in an assembling hole formed at one side of the outer cylinder by an adjusting hole,
Wherein a signal generated by the signal sensing unit is sensed on one side of the assembler and sound is generated by the sound generator.

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