KR100765460B1 - Hydraulic system for a hemming work and operation method of the same - Google Patents

Abstract

A hydraulic system for a hemming operation and a method of operating the same are provided to maximize the efficiency of the hemming operation by organically constructing pumps and varieties of electronic valves, and extend the service life of the system and maximize the productivity by performing lifting and lowering processes of a cylinder rod of a hydraulic cylinder respectively in respectively optimized multiple steps. In a hydraulic system for a hemming operation, which hydraulic system is connected to a hydraulic cylinder(59) having a cylinder rod connected to a mold to perform a hemming operation of car body panels, the hydraulic system comprises: a double pump(6) driven by electric motors(2,3) and consisted of a combination of a high pressure pump(H) and a first low pressure pump(L1); a second low pressure pump(7) driven by an electric motor; an oil tank(1) for supplying oil to the double pump and the second low pressure pump; a first electronic valve(8a) for performing loading and unloading operations of the first low pressure pump; a second electronic valve(8b) for performing loading and unloading operations of the second low pressure pump; a third electronic valve(30a) for straightly transferring a flux of the first low pressure pump to the hydraulic cylinder; a fourth electronic valve(30b) for controlling a flux supplied into the hydraulic cylinder; a fifth electronic valve(35a) for lowering the cylinder rod, and a sixth electronic valve(35b) for lifting the cylinder rod; a seventh electronic valve(33a) for supplying a flux of the high pressure pump to the hydraulic cylinder; and an eighth electronic valve(34) for performing loading and unloading operations of the high pressure pump.

Description

Hydraulic system for hemming work and its operation {Hydraulic system for a hemming work and operation method of the same}

1 is a view showing a schematic configuration of a conventional hydraulic system for hemming operation.

2 is a plan view of a hydraulic apparatus according to the present invention.

3 is a front view of FIG. 2;

4 is a side view of FIG. 3;

5 is a hydraulic circuit diagram showing the overall configuration of a hydraulic system of a hydraulic apparatus according to a preferred embodiment of the present invention.

6 shows a timing chart for driving the hydraulic device of FIG.

7 to 12 is a circuit diagram for each step for explaining the process of operating the hydraulic device of Figures 3 to 5.

Figure 13 is a block diagram showing the operation sequence of the hydraulic cylinder by the hydraulic device of the present invention.

<Description of the symbols for the main parts of the drawings>

1: oil tank 2,3: electric motor

6: double pump 7: 2nd low pressure pump

8a, 8b: Solenoid valve 19: Oil cooler

28, 29: relief valve 30: solenoid valve

31: Throttle valve 33a, 33b, 34: Solenoid valve (poppet valve)

35: main solenoid valve 36: throttle and check valve

37: sequence valve 38: pilot check valve

40a, 40b, 40c, 40d, 40e: solenoid valves 42, 44, 46: logic elements

43, 45, 47: logic cover 48: relief valve

49: pilot check valve 51a, 51b: pressure switch

59: hydraulic cylinder 60: manifold block

100: hydraulic system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic device, and more particularly, to a hydraulic device for a hemming operation of a body panel such as an engine hood or a trunk of an automobile.

In general, an engine hood or trunk of an automobile is subjected to a hemming process of overlapping two panels and then bending and pressing the ends of the outer panel toward the inner panel.

1 is a view showing a schematic configuration of a conventional hydraulic system for hemming operation, looking at the specific configuration of the direction switching valve for controlling the flow rate of the oil pumped from the pumping member 210 and the pumping member 210 connected to the oil tank The rod 234 is coupled to the mold 220 for the hemming operation, the cylinder member 230 for controlling the lifting of the mold by receiving oil by the operation of the directional valve 220, and the cylinder member 230. Sensor member 240 for detecting the lifting operation of the) and the profile valve 250 is operated through the detection signal of the sensor member 240 to control the lifting speed of the rod 231 of the cylinder member (230). . Such a conventional valve has been disclosed in Patent No. 460877 “Heming Machine” as an example of a hemming pressurization device.

Conventional hemming pressurization apparatus, including the above-described apparatus, has a problem in that the lifting speed of the hydraulic cylinder and the like cannot be precisely adjusted, thereby imparting pressure on the hydraulic apparatus or other components. In addition, a problem has been raised that the rod of the hydraulic cylinder for the hemming operation is not optimized in terms of the efficiency of the hemming operation because the rod is moved up and down at a constant speed or is operated too fast or only at a low speed. These problems are not easily improved because of the difficult design and control of the hydraulic system. In addition, the existing hemming pressurized hydraulic devices are simple in structure and somewhat inadequate to automate the entire process. Therefore, a hydraulic control system capable of more precise and smooth control is required to execute the hemming process precisely and consistently.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to organically configure a pump and various solenoid valves to control a hydraulic cylinder coupled to a hemming mold so as to be optimized for a hemming operation. To maximize efficiency.

Another object of the present invention is to ensure that the lifting and lowering of the cylinder rod of the hydraulic cylinder is achieved in each optimized multi-step to facilitate smooth and safe operation of the hydraulic system, such as hydraulic cylinders and hydraulic devices to increase the life of the device and increase productivity Is to maximize.

In order to achieve the above technical problem of the present invention, the present invention provides a hydraulic device for a hemming operation connected to a hydraulic cylinder having a cylinder rod coupled to a mold for a hemming operation of the body panel, to supply hydraulic pressure to the hydraulic cylinder. A double pump driven by an electric motor and configured to combine a high pressure pump and a first low pressure pump, and a second low pressure pump driven by an electric motor to supply hydraulic pressure to the hydraulic cylinder, the double pump and the first pump. 2 an oil tank for supplying oil to the low pressure pump, a first solenoid valve connected to the first low pressure pump to perform loading and unloading of the first low pressure pump, and a second low pressure pump connected to the second low pressure pump A second solenoid valve for loading and unloading the low pressure pump, the first low pressure pump and the hydraulic cylinder A third solenoid valve for providing a flow rate of the first low pressure pump directly to the hydraulic cylinder, the first low pressure pump being provided on the first low pressure pump pressure line to be connected to the first low pressure pump pressure line; Connecting the fourth solenoid valve, the first low pressure pump and the second low pressure pump, and the hydraulic cylinder to adjust the flow rate supplied to the hydraulic cylinder by passing the flow rate through the throttle valve connected to the first low pressure pump pressure line. And a fifth solenoid valve for lowering the cylinder rod, a sixth solenoid valve for raising the cylinder rod, and a high pressure pump for connecting the high pressure pump and the hydraulic cylinder. A seventh solenoid valve and the high pressure for supplying a flow rate of the high pressure pump to the hydraulic cylinder as Is connected to print provides a hemming working hydraulics, it characterized in that the configuration including the eighth solenoid valve to perform the loading and unloading operations of the high-pressure pump.

Here, the flow rate supplied to the hydraulic cylinder when the cylinder rod is lowered is provided on a drain line branched from the pressure line connecting the fifth solenoid valve and the hydraulic cylinder to the oil tank so that the flow rate does not leak to the oil tank. It is preferable that a ninth solenoid valve is provided to prevent this.

When the cylinder rod is lowered, it is preferable to provide a tenth solenoid valve for draining oil in the hydraulic cylinder to the oil tank by operating a check valve provided on a drain line connecting the lower end of the hydraulic cylinder and the oil tank. Do.

An eleventh solenoid valve provided on a drain line connecting the lower end of the hydraulic cylinder and the oil tank when the cylinder rod is rapidly lowered to recirculate the flow rate discharged from the lower end of the hydraulic cylinder to the upper end of the hydraulic cylinder; It is desirable to.

It is preferable that a twelfth solenoid valve is provided on the pressure line connected to the upper end of the hydraulic cylinder so as to maintain the high pressure formed at the upper end of the cylinder during the hemming pressurization operation after the lowering of the cylinder rod. .

And a thirteenth solenoid valve for operating a check valve provided on a flow path branched from a drain line connecting the upper end of the hydraulic cylinder and the oil tank when the cylinder rod is rapidly risen to drain the flow rate of the upper end of the hydraulic cylinder. It is desirable to.

In the above-described hemming operation hydraulic apparatus, the ninth solenoid valve, the tenth solenoid valve, the eleventh solenoid valve, the twelfth solenoid valve, and the thirteenth solenoid valve may be selectively applied, but all are preferably applied.

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Preferably, the third solenoid valve and the fourth solenoid valve operate as components of one double acting solenoid valve, and the fifth solenoid valve and the sixth solenoid valve are also constituted as components of one double acting solenoid valve. It is desirable to work.
The hydraulic device is preferably operated to complete one stroke by operating in the order of low speed, high speed, low speed, hemming pressure, extraction, low speed, high speed and low speed of the cylinder rod.

Hereinafter, with reference to the accompanying drawings will be described in more detail the configuration and operation of the present invention.

Figure 2 is a plan view of the hydraulic system according to the present invention, Figure 3 is a front view of Figure 2, Figure 4 is a side view of Figure 3, Figure 5 is the overall configuration of the hydraulic system of the hydraulic device according to a preferred embodiment of the present invention It is a hydraulic circuit diagram showing. The hydraulic apparatus 100 of the present invention is composed of a double pump 6, which is composed of a combination of an oil tank 1, an electric motor 2, 3, a high pressure pump H, and a first low pressure pump L1. 2 low pressure pump (7, L2), hydraulic cylinder (59), first solenoid valve (8a), second solenoid valve (8b), third solenoid valve (30a), fourth solenoid valve (30b), fifth solenoid Valve 35a, 6th solenoid valve 35b, 7th solenoid valve 33a, 8th solenoid valve 34, 9th solenoid valve 40d, 10th solenoid valve 40a, 11th solenoid valve ( 40b), the 12th solenoid valve 33b, the 13th solenoid valve 40c, and the 14th solenoid valve 40e are comprised. A hemming working die (not shown) is attached to one end of the cylinder rod of the hydraulic cylinder 59.

Reference numerals 42, 44, and 46 are logic elements for flow control, and 43, 45, and 47 are logic covers of the respective logic elements.

The double pump 6 of the present invention is a variable pump composed of a combination of a high pressure pump H and a first low pressure pump L1, and the second low pressure pump 7 is a large capacity low pressure pump. Preferably, both the double pump 6 and the second low pressure pump 7 are piston type.

The first solenoid valve 8a is for loading and unloading the first low pressure pump L1, and the second solenoid valve 8b is for loading and unloading the second low pressure pumps 7 and L2. Do the work. The third solenoid valve 30a and the fourth solenoid valve 30b are components of one double acting solenoid valve, and the third solenoid valve 30a controls the flow rate of the first low pressure pump L1 by the throttle valve ( It is for supplying the total flow rate of the first low pressure pump L1 to the upper end of the hydraulic cylinder 59, that is, the cylinder head side, without passing through the throttle valve 31, and the fourth solenoid valve 30b is It is for adjusting the flow volume supplied to the cylinder head side by passing the flow volume of the 1 low pressure pump L1 through the throttle valve 31. The fifth and sixth solenoid valves are components of one double acting solenoid valve, and are the main valves for the lifting operation of the cylinder rod of the hydraulic cylinder 59. That is, the fifth solenoid valve 35a lowers the cylinder rod, and the sixth solenoid valve 35b raises the cylinder rod. Preferably, the seventh solenoid valve 33a is a poppet valve, and sends the flow rate of the high pressure pump H to the cylinder head to lower the cylinder rod. Preferably, the eighth solenoid valve 34 is also a poppet valve, and performs the loading and unloading operation of the high pressure pump (H). The ninth solenoid valve 40d blocks the logic element 46 so that the flow rate discharged from the pump does not leak into the oil tank 1 when the cylinder rod descends. The tenth solenoid valve 40a operates the pilot check valve 38 when the cylinder rod descends to circulate the flow rate discharged from the hydraulic cylinder 59 to the oil tank 1. The eleventh solenoid valve 40b sends the differential flow on the cylinder rod side back to the cylinder head side through the logic element 42 when the cylinder rod is rapidly descending to induce the cylinder rod to descend at a high speed. The twelfth solenoid valve 33b is preferably a poppet valve, and serves to block the high pressure formed on the cylinder head side during the lowering and the hemming pressurization of the cylinder rod so as to prevent the pressure from being pushed through the logic element 44. The thirteenth solenoid valve 40c operates the pilot check valve 49 in the depressurization process to be described later to remove the high pressure on the cylinder head side, or the pilot check valve 49 when the cylinder rod rises at high speed to operate the cylinder head. A large flow rate of the side serves to pump the oil tank (1). The 14th solenoid valve 40e is to prevent the cylinder from sagging by removing residual pressure remaining on the cylinder rod side by turning off the valve automatically when the main power is cut off during operation of the hydraulic system. It must be in the ON state.

The relief valve 29 is installed in order to prevent damage to the system due to abnormal pressure of the double pump 6 and the second low pressure pump 7, and the relief valve 28 controls the pressure of the double pump 6. To adjust the desired hemming force. The sequence valve 37 is a valve for primarily controlling the fall prevention and the low speed falling speed by the weight of the cylinder rod. The relief valve 48 is a safety valve provided for controlling the abnormal pressure generated on the cylinder rod side when the cylinder rod is lowered. The pressure switch 51b is for setting the pressure state at the completion of the hemming operation and transmits an electrical signal relating to the pressure state at the completion of the hemming to a logic controller (PLC). The pressure switch 51a is for setting the ideal hemming pressure. Reference numeral 19 denotes an oil cooler.

Hereinafter, the operation principle of the present invention will be described in detail with reference to the drawings of FIGS. 6 to 13.

6 is a view illustrating a timing chart for driving the hydraulic apparatus of FIG. 3, and FIGS. 7 to 12 are operation diagrams for each step for explaining a process of operating the hydraulic apparatus of FIGS. 3 to 5, and FIG. 13. Is a block diagram showing the operation sequence of the hydraulic cylinder by the hydraulic apparatus of the present invention.

The hydraulic device 100 for a hemming operation of the present invention is a one-stroke lowering, high-speed lowering, lowering speed, hemming pressurization during one stroke when defining that the cylinder rod of the hydraulic cylinder 59 completes the lowering and raising once. It operates in the order of low speed rising, high speed rising and low speed rising. The lowering step of the cylinder rod when the lowering start of the lowering can be omitted and can be operated immediately in the order of the high speed descending and the low speed lowering, and a depressing step can be added between the hemming pressurization and the high speed raising step. However, it is more desirable to allow the device to undergo a slowing down step at the initial start of the cylinder rod because it can reduce the burden on the device and extend the life of the device.

Referring to the timing chart of Figure 6 and the step-by-step diagrams look at the operation of the present invention as follows. In FIG. 6, SOL 1 to SOL 14 mean the first solenoid valves to the fourteenth solenoid valves, respectively, FIG. 7 is a low speed falling step, FIG. 8 is a high speed falling step, FIG. 9 is a hemming pressurizing step, and FIG. 11 is a hydraulic circuit diagram showing a low speed rising step and FIG. 12 a high speed rising step. In the present invention, the two slow descent stages before and after the fast descent stage operate with the same mechanism, and the two slow descent stages before and after the rapid descent stage also operate with the same mechanism. Therefore, the drawings are not shown in duplicate. In each figure, the part represented by the thick solid line or the thick dashed line represents the pressure line P, the thick one-dot chain line represents the drain line D, and the part represented by the thin double-dotted line represents the manifold block (MB). 60.

In the low-speed falling step, as shown in FIG. 7, the first solenoid valve 8a, the fourth solenoid valve 30b, the fifth solenoid valve 35a, the seventh solenoid valve 33a, and the eighth solenoid valve 34 The ninth solenoid valve 40d, the tenth solenoid valve 40a, the twelfth solenoid valve 33b, and the fourteenth solenoid valve 40e are turned on to operate.

In the high speed descending step, as shown in FIG. 8, the first solenoid valve 8a, the second solenoid valve 8b, the third solenoid valve 30a, the fifth solenoid valve 35a, and the seventh solenoid valve 33a are provided. , The eighth solenoid valve 34, the ninth solenoid valve 40d, the tenth solenoid valve 40a, the eleventh solenoid valve 40b, the twelfth solenoid valve 33b, and the fourteenth solenoid valve 40e are turned on. It works. In this high speed lowering step, the eleventh solenoid valve 40b circulates the differential flow on the cylinder rod side to the cylinder head side through the logic element 42 to smoothly lower the high speed of the cylinder rod.

Since the slow descent step operates in the same process as in the slow descent step before the fast descent, overlapping description is omitted.

When the cylinder rod combined with the mold is completed on low speed and placed on the workpiece, the machining part of the target panel is pressed to hemming. If this is called a hemming pressurization step, as shown in FIG. 9, the 1st solenoid valve 8a, the 3rd solenoid valve 30a, the 5th solenoid valve 35a, the 7th solenoid valve 33a, The eighth solenoid valve 34, the ninth solenoid valve 40d, the tenth solenoid valve 40a, the twelfth solenoid valve 33b, and the fourteenth solenoid valve 44e are turned on to operate. At this time, the time for pressurizing the work object is preferably about 2 to 3 seconds.

When the hemming pressurization is completed, a depressurization step is performed to depressurize the cylinder before raising the cylinder rod. In the depressing step, as shown in FIG. 10, the first solenoid valve 8a, the third solenoid valve 30a, the tenth solenoid valve 40a, the twelfth solenoid valve 33b, and the thirteenth solenoid valve 40c. ) And the fourteenth solenoid valve 40e are turned on to operate. At this time, the thirteenth solenoid valve 40c operates the pilot check valve 49 to remove the high pressure formed at the cylinder head side.

In the subsequent low speed rising step, as shown in Fig. 11, the first solenoid valve 8a, the fourth solenoid valve 30b, the sixth solenoid valve 35b and the fourteenth solenoid valve 40e are turned on to operate. At this time, the throttle valve 31 becomes a valve for adjusting the rising speed.

In the high speed rising step, as shown in Fig. 12, the first solenoid valve 8a, the second solenoid valve 8b, the third solenoid valve 30a, the sixth solenoid valve 35b, and the thirteenth solenoid valve 40c. And the fourteenth solenoid valve 40e is turned on to operate. At this time, the thirteenth solenoid valve 40c operates the pilot check valve 49 to drain a large flow rate on the cylinder head side to the oil tank 1.

After that, the cylinder rod returns to its original position through the low speed rising step to complete one stroke. The low speed rising operation in this step operates in the same manner as the low speed rising step described above, and thus redundant description will be omitted.

Hydraulic device 100 of the present invention operating in the above process by configuring the differential circuit to use the differential flow rate at the high speed of the cylinder rod to ensure high-speed operation safely and quickly, the double pump (6) and the second By constructing and operating the low pressure pump 7 together, there is an advantage that the hydraulic cylinder can be more precisely controlled. The pump configuration of the present invention is a structure capable of transmitting or draining the hydraulic pressure corresponding to exactly the distance that the cylinder rod of the hydraulic cylinder moves, so that a more precise hemming operation is possible.

Pumps and valves on each hydraulic line and drain line of the hydraulic device of the present invention are optimized to be electronically controlled by logic, which is advantageous for automation and can freely adjust the lifting speed of the cylinder rod of the hydraulic cylinder. There is an advantage.

In addition, in the present invention, by optimizing and arranging the double pump combined with the high pressure pump and the low pressure pump and a separate large capacity low pressure pump, the cylinder rod of the hydraulic cylinder can be operated more safely and precisely, and particularly, a differential circuit is constructed at a high speed drop. As a result, the cylinder's descending speed is greatly increased, but there are no side effects or safety problems caused by the high speed descending.

In addition, it is advantageous in the automation of the device by designing a combination of various solenoid valves and logic elements, there is an advantage that easy to check and maintenance of components such as each valve.

Claims (10)

In the hemming work hydraulics connected to a hydraulic cylinder having a cylinder rod coupled to the mold for hemming the body panel, A double pump driven by an electric motor and configured to combine a high pressure pump and a first low pressure pump to supply hydraulic pressure to the hydraulic cylinder; A second low pressure pump driven by an electric motor to supply hydraulic pressure to the hydraulic cylinder; An oil tank for supplying oil to the double pump and the second low pressure pump; A first solenoid valve connected to the first low pressure pump to perform loading and unloading of the first low pressure pump; A second solenoid valve connected to the second low pressure pump to perform loading and unloading of the second low pressure pump; A third solenoid valve provided on a first low pressure pump pressure line connecting the first low pressure pump and the hydraulic cylinder to directly transfer a flow rate of the first low pressure pump to the hydraulic cylinder; A fourth solenoid valve provided on the first low pressure pump pressure line to regulate a flow rate supplied to the hydraulic cylinder by passing a flow rate of the first low pressure pump through a throttle valve connected to the first low pressure pump pressure line; ; A fifth solenoid valve provided on the low pressure pump pressure line connecting the first low pressure pump and the second low pressure pump and the hydraulic cylinder, and a sixth solenoid valve for raising the cylinder rod; A seventh solenoid valve provided on a high pressure pump pressure line connecting the high pressure pump and the hydraulic cylinder to supply a flow rate of the high pressure pump to the hydraulic cylinder; And An eighth solenoid valve connected to the high pressure pump to perform loading and unloading of the high pressure pump; Hydraulic device for hemming operation, characterized in that comprising a. The method of claim 1, It is provided on a drain line branched from the pressure line connecting the fifth solenoid valve and the hydraulic cylinder to the oil tank so that the flow rate supplied to the hydraulic cylinder does not leak to the oil tank when the cylinder rod descends. Hemming work hydraulics, characterized in that the ninth solenoid valve is provided for. The method of claim 1, A tenth solenoid valve is provided for draining oil in the hydraulic cylinder to the oil tank by operating a check valve provided on a drain line connecting the lower end of the hydraulic cylinder and the oil tank when the cylinder rod is lowered. Hydraulics for hemming operations. The method of claim 1, An eleventh solenoid valve provided on a drain line connecting the lower end of the hydraulic cylinder and the oil tank when the cylinder rod is rapidly lowered to recirculate the flow rate discharged from the lower end of the hydraulic cylinder to the upper end of the hydraulic cylinder; Hydraulic device for hemming work, characterized in that. The method of claim 1, A 12 th solenoid valve is provided on the pressure line connected to the upper end of the hydraulic cylinder to block the pressure from the upper end of the cylinder to maintain the high pressure formed on the upper end of the cylinder during the hemming pressurization operation after the lowering of the cylinder rod. Hydraulic device for hemming work. The method of claim 1, And a thirteenth solenoid valve for operating a check valve provided on a flow path branched from a drain line connecting the upper end of the hydraulic cylinder and the oil tank when the cylinder rod rises at a high speed to drain the flow rate of the upper end of the hydraulic cylinder. Hydraulic device for hemming work, characterized in that. The method of claim 1, It is provided on the drain line branched from the pressure line connecting the fifth solenoid valve and the hydraulic cylinder extending to the oil tank so that the flow rate supplied to the hydraulic cylinder when the cylinder rod is lowered does not leak into the oil tank. A ninth solenoid valve for; A tenth solenoid valve for operating the check valve provided on the drain line connecting the lower end of the hydraulic cylinder and the oil tank when the cylinder rod is lowered to drain oil in the hydraulic cylinder to the oil tank; An eleventh solenoid valve provided on a drain line connecting the lower end of the hydraulic cylinder and the oil tank when the cylinder rod is rapidly lowered to recirculate the flow rate discharged from the lower end of the hydraulic cylinder to the upper end of the hydraulic cylinder; A twelfth solenoid valve provided on a pressure line connected to an upper end of the hydraulic cylinder to block a pressure from the upper end of the cylinder so as to maintain a high pressure formed at the upper end of the cylinder during the hemming pressurization operation after the lowering of the cylinder rod; And A thirteenth solenoid valve for operating a check valve provided on a flow path branched from a drain line connecting the upper end of the hydraulic cylinder to the oil tank when the cylinder rod is rapidly rising; Hydraulic device for hemming operation comprising a. The method according to any one of claims 1 to 7, And the third solenoid valve and the fourth solenoid valve are configured in one double acting solenoid valve. The method according to any one of claims 1 to 7, And the fifth solenoid valve and the sixth solenoid valve are configured in one double acting solenoid valve. In the method of operating the hydraulic device of claim 7, The hydraulic device is the operation of the hydraulic device for the hemming operation, characterized in that the cylinder rod is operated to complete the first stroke by operating in the order of low speed, low speed, hemming pressurization, extracting, low speed rising, high speed rising and low speed rising. Way.

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