JPH0647330A - Discharge device - Google Patents

Abstract

PURPOSE:To obtain a discharge device free from clogging having a capability of adjusting the discharge amount of a liquid which is sedimentation-prone. CONSTITUTION:This discharge device consists of a device G which detects the amount of a liquid discharged from a discharger F, a bypass C which bypasses the discharger, a flow adjustment device D which adjusts the flow of the bypass, and a control device H which adjusts the capacity of a capacity- variable pump so that the amount of liquid detected by a discharged amount detection device falls within the range of a specified discharged amount to which a specified adjustment width is added or from which said width is subtracted and adjusts the flow adjustment device so that the amount detected by the discharged amount detection device is equal to a specified discharged amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge device, and more particularly, to a discharge device having excellent discharge amount adjusting ability.

[0002]

2. Description of the Related Art For example, a mold coating agent applied to a cavity for protecting a casting mold contains a large amount of solid matter such as metal pieces and water glass, and has a high viscosity and is likely to cause precipitation. A technique for discharging such a fluid that easily precipitates from a discharging device such as a discharging nozzle is disclosed in Japanese Utility Model Laid-Open No. 61-8764.
No. 0 publication. In this technique, a circulation path is provided between the tank and the discharger, and a fluid is pumped into the circulation path by a pump for circulation. In this way, the fluid constantly circulates, and the pump having a high discharge pressure and a large discharge amount can be used.

When the pump has a high discharge pressure and a large discharge amount, the precipitate is easily sent out of the pump, and the occurrence of pump clogging can be suppressed. In addition, since the fluid constantly circulates in the circulation path, precipitation does not easily occur.

[0004]

As described above, in the conventional discharge device, precipitation or the like is prevented by vigorously circulating the fluid with a pump having a high discharge pressure and a large discharge amount. However, it is difficult to accurately control the discharge amount. This is because it is difficult to finely adjust the capacity of the pump when the pump has a high discharge pressure and a large discharge amount as described above. Therefore, the present invention is intended to improve the discharge amount adjusting ability.

[0005]

Therefore, in the present invention, as schematically shown in FIG. 1, the liquid moving body that easily precipitates is moved by the variable capacity pump E to the tank A and the discharger F. In a discharge device that discharges the fluid from the discharger F by circulating a circulation path B provided therebetween, a device G that detects the amount of the fluid discharged from the discharger F, and the discharger Bypass C for bypassing the device F, and a flow rate adjusting device D for adjusting the flow rate of the bypass C
Then, the capacity of the variable capacity pump E is adjusted so that the amount detected by the discharge amount detection device G is within a range obtained by increasing or decreasing the predetermined adjustment range to the predetermined discharge amount, and then the discharge amount detection device G is adjusted. A discharge device was created by adding a control device H for adjusting the flow rate adjusting device D so that the detected amount becomes a predetermined discharge amount.

[0006]

According to the present invention, because of the bypass passage C,
On the pump E side, the fluid can be sent out in a state of high discharge pressure and large discharge amount, and the precipitation of the pump E can be prevented. On the other hand, since the flow rate of the bypass C can be adjusted, the discharge amount can be adjusted more finely than in the case where the pump capacity is adjusted, and the discharge amount adjustment accuracy is greatly improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment embodying the present invention will be described. FIG. 2 shows the system configuration of the discharge device according to this embodiment. This discharge device embodies the present invention in order to apply the mold coating agent 6 which contains a large amount of solid matter such as metal pieces or water glass and which easily precipitates to the cavity 28b of the casting mold 28.

The mold coating agent 6 is stored in the tank 8, and the stirring blade 4 is rotated by the motor 2 in the tank 8 to prevent precipitation. A delivery pipe 10 extends from the tank 8, and a variable capacity pump 12 having a high discharge pressure and a large discharge capacity is provided in the middle of the discharge pipe 10. Since the pump 12 vigorously sends out the coating agent 6, pump clogging does not occur. The pump 12 sends the coating material 6 to the flexible pressure resistant hose 14. A discharge gun 24 is attached to the tip of the pressure-resistant hose 14, and the coating agent 6 not discharged from the discharge gun 24 is the flexible hose 16 and the return pipe 2.
It is returned to the tank 8 via 2. By the delivery pipe 10, the flexible hoses 14, 16 and the return pipe 22,
A circulation path is formed between the tank 8 and the discharge gun 24.

A bypass passage 18 that bypasses the discharge gun 24 is provided in the circulation passage, and a flow rate adjusting valve 20 is provided in the middle of the bypass passage 18. Figure 3
As shown in FIG. 1, the flow rate control valve 20 includes a flexible hose 18 a provided in the middle of the bypass passage 18 and a ring bag 60 having a floating bag shape surrounding the hose 18 a.
It consists of and. When high pressure air is supplied from the port 60a into the ring tube 60, the ring tube 6
The inner diameter of 0 is reduced to limit the flow rate of the bypass passage 18. On the contrary, when high-pressure air is discharged from the ring tube 60 via the port 60a, the inner diameter of the ring tube 60 is expanded and the flow rate of the bypass passage 18 is increased. According to the flow rate adjusting valve 20, the pipeline is smooth regardless of the size of the throttled state, and even if it is a coating agent that is easily precipitated, it does not precipitate. If this is a normal on-off valve, stagnation occurs in the closed state, and precipitates are likely to accumulate there.

The flow rate adjusting valve is not limited to this, and as shown in FIG. 4, for example, a type in which the flexible bypass conduit 18C is deformed by the plunger 70 which advances and retracts by the cylinder 72. But it's okay.

As shown in FIG. 2, the discharge gun 2
The robot 4 is attached to the hand of the robot 32, and the robot 32 controls the position and posture of the discharge gun 24. By the movement of the robot 32, the mold 2
The mold coating agent 6 is applied to the cavity 28b of No. 8 along the robot movement trajectory. The ejection gun 24 atomizes the coating material 6 and sprays it. At the tip of the robot 32, a pair of light emitting element 26a and light receiving element 26b are attached so as to cross the tip of the ejection gun 24. The pair of light emitting elements / light receiving elements 26a and 26b is used to measure the ejection amount by utilizing the phenomenon that the light reception signal changes depending on the amount of the coating agent 6 ejected from the ejection gun 24.

A pressure resistant air hose 36 is connected to the ring tube 60 of the flow rate adjusting valve 20, and the pressure resistant air hose 36 is connected to an air source 42 via a solenoid valve 40. The solenoid valve 40 can be switched between a state in which the ring tube 60 and the air source 42 are communicated with each other and a state in which the ring tube 60 is open to the atmosphere. A pressure sensor 38 is attached to the pressure-resistant air hose 36, and a signal related to the pressure in the ring tube 60 and, in turn, the open / close state of the flow rate adjusting valve 20 is detected.

The discharge capacity and discharge amount of the variable capacity pump 12 can be switched in multiple stages, and the capacity can be switched in multiple stages. In this embodiment, 2 kw to 4 k
It is possible to adjust in stages between w. Further, the discharge device is provided with an alarm device 44.

The pump 12, the solenoid valve 40, the robot controller 34 for controlling the robot 32, and the alarm device 44 are connected to the CPU 48 via the I / F 46. Further, a light receiving signal relating to the discharge amount and a signal indicating the pressure inside the ring tube 60 are transmitted via the I / F 46 to the CPU 4
8 can be input. RAM 50 for CPU 48
And ROM 52 are connected to form a computer.
A program for executing the processing procedure shown in FIGS. 5 and 6 is stored in the ROM 52, and the CPU 48 performs the processing of FIGS. 5 and 6 based on this program. As a result, the variable capacity pump 12, the flow rate adjusting valve 20, the robot 32, and the alarm device 44 are controlled as follows.

The processes shown in FIGS. 5 and 6 are processes executed so that an appropriate amount of the coating agent 6 is discharged from the discharge gun 24. At present, it is executed every time the discharge device is started. To be done. However, if the discharge amount changes significantly during operation, it may be executed at an appropriate timing during operation.

When this process starts in step S0, the pressure in the ring tube 60 is adjusted to an intermediate predetermined value in step S2. For this purpose, the signals from the solenoid valve 40 and the pressure sensor 38 are used. Here, the intermediate predetermined value is preset to a value at which the flow rate adjustment state of the flow rate adjustment valve 20 is just in the middle of the adjustable width. From this state, when the pressure in the ring tube 60 is maximized to reduce the bypass amount, the discharge amount increases by ΔQV, and conversely, when the pressure is set to the minimum and the bypass amount is increased, the discharge amount decreases by ΔQV. That is, in step S2, the flow rate adjusting valve 20 can adjust the discharge amount by ± ΔQV. In this state, next, the pump 12 starts to be driven in step S4. Here, it is driven by the pump capacity at the time of the previous operation. In this state, the ejection amount is detected from the light receiving signal of the light receiving element 26b, and this is stored as Q (step S
6). Next, in step S8, a possible increase ΔQU and a possible decrease ΔQD are calculated from the current pump capacity. Now Fig. 7 (A)
As shown in, when the pump 12 is currently driven in a state close to the maximum capacity, the increase amount of the discharge amount when this is increased to the maximum capacity (this is the possible increase amount ΔQU here) is small. On the contrary, when the pump is reduced to the minimum capacity, the reduction range of the discharge amount (this is the possible reduction amount ΔQD here) is relatively large. On the other hand, as shown in FIG. 7C, when the pump 12 is used with a relatively low capacity, the possible increase amount ΔQU is large and the possible decrease amount ΔQD is small. In this way, the possible increase ΔQU and the possible decrease ΔQD are determined by the pumping capacity at that time, and therefore they are obtained in step S8 of FIG. In step S10, the current discharge amount Q is set to the allowable maximum amount QMAX and the possible adjustment amount ΔQ.
It is determined whether the value is less than or equal to the value obtained by adding V. Here, the maximum allowable amount QMAX is the maximum amount that allows proper coating work, and the possible adjustment amount ΔQV is the flow rate adjusting valve 20 as described above.
Adjustable amount.

When the condition of step S10 is not satisfied, that is, as shown in FIG.
Even if the diaphragm state of is adjusted, the discharge amount Q is still the maximum allowable amount QM.
If it exceeds AX, then step S12 is performed.
To execute. The left side of step S12 is the discharge amount when the pump capacity is minimized, while the right side is the flow control valve 20.
Is a condition under which the discharge amount when the discharge amount is opened to the maximum and the discharge amount is minimized becomes the maximum allowable amount QMAX. If YES here, that is, if the discharge amount can be made equal to or less than the allowable maximum amount QMAX by lowering the pump capacity as shown in FIG. 7B, the pump capacity is lowered by one step in step S14, and after step S6. And try again. Meanwhile, FIG.
As illustrated in (C), if the pump capacity cannot be reduced to the allowable maximum amount QMAX or less even if the pump capacity is the lowest, the proper discharge amount cannot be adjusted by adjusting the pump capacity or the flow rate adjusting valve 20. In this case, step S12 becomes no.
Therefore, in this case, in order to perform processing for moving the robot 32 at high speed as described later, the speed increasing flag is turned on in step S16 and the processing of FIG. 5 is continued. This will be described later. When it is found in step S12 that the discharge amount can be made equal to or less than the allowable maximum amount by lowering the pump capacity, the pump capacity is set to one paragraph in step S14. Then, while this process is being repeated, step S10 becomes YES in either case. Alternatively, as shown in FIG. 7A, when the discharge amount Q is originally small, step S10 becomes YES from the beginning. In this case, step S18 is next determined. Here, QMIN in the right side is the minimum permissible amount that allows proper application work. Also, ΔQV is the adjustable range by the flow rate adjusting valve 20 as before. Since the flow rate adjusting valve 20 is now in the intermediate throttle state, the discharge amount from the discharge gun 24 is increased by closing it to the maximum.
This increase is ΔQV. Now, even if the flow rate in the state where the flow rate adjusting valve 20 is in the intermediate throttle state is smaller than QMIN by ΔQV, the actual discharge amount can be made equal to or more than the allowable minimum amount QMIN by closing the flow rate adjusting valve 20. In this case, step S18 becomes yes. On the other hand, step S18
If is no, it corresponds to a case where the flow rate adjusting valve 20 cannot be adjusted. Therefore, in this case, step S2
At 0, see if the discharge rate can be adjusted by maximizing the pump capacity. Here, since the concept is the same as that in step S12, detailed description will be omitted. If YES in step S20, that is, if the required discharge amount can be secured by increasing the pump capacity, the pump capacity is increased by one step in step S22. Then, step S6 and subsequent steps are repeated again. In this way, the process of step S14 or S22 is repeated until both steps S10 and S18 are YES. Step S14
The adjustment of the pump capacity in step S22 is performed in step S
It is repeated until both 16 and S18 become yes.

In this way, when the pump capacity is adjusted and the discharge amount can be adjusted between the allowable minimum amount QMIN and the allowable maximum amount QMAX by the adjustment of the flow rate adjusting valve 20, the steps after step S26 are performed. To be executed. Here, it is first determined whether the actual discharge amount Q is equal to or larger than the maximum allowable amount QMAX.
At 28, the air pressure in the ring tube 60 is reduced to increase the bypass amount and decrease the discharge amount. This is continued until step S26 becomes NO. On the other hand, the flow rate Q is the minimum allowable amount QMIN
If not, step S30 becomes yes. At this time, in step S32, the air pressure is increased to reduce the bypass amount and increase the discharge amount. This is continued until step S30 becomes NO. By repeating step S28 or step S32 until both steps S26 and S30 are NO, the ejection amount Q becomes larger than the allowable minimum amount QMIN and smaller than the allowable maximum amount QMAX. The flow rate adjustment is executed in this way, and the process ends (step S36). Now, the process in the case where the pump capacity cannot be completely adjusted, that is, in the case where step S12 or S20 is NO will be described with reference to FIG. The process of FIG. 6 is performed when the discharge amount Q is still too large even if the pump capacity is lowered (at this time, step S12 is NO and the speed increasing flag is turned on), and the discharge amount is still increased even if the pump capacity is increased. This is executed when Q is too small (at this time, step S20 is NO and the deceleration flag is on). If the discharge amount is too large, the robot 32 can increase the speed at which the discharge gun 24 is moved to achieve proper coating. If the discharge amount is too small, the movement speed of the discharge gun 24 can be reduced to achieve proper coating. Can The process of FIG. 6 realizes this.

When the processing of FIG. 6 is started, first, in step S40, a warning is issued that the robot cannot respond unless the robot speed is changed. Next, the applicable width is calculated from the current robot speed. Here, the applicable width ΔQU1 indicates the increase amount of the discharge amount that can be handled by increasing the speed of the robot to the maximum, and the ΔQD1 indicates the decrease amount of the discharge amount that can be handled by decelerating the robot to the minimum speed. ing. Then, in step S44, it is determined whether the speed increase flag is on or off. If it is on, the pump capacity is minimized to reduce the discharge amount as much as possible. On the other hand, if it is off, the pump capacity is maximized to increase the discharge amount as much as possible. In this state, the discharge amount is then re-detected (step S50), and it is further determined whether the flow rate adjusting valve 20 can adjust the discharge amount (S52). The first is no, and the process proceeds to step S54. In step S54, it is determined whether or not the acceleration flag is on. If it is on, it is checked whether or not proper application is possible by maximizing the speed of the robot (step S58). If yes, the robot speed is increased by one step (S64), and step S42 and subsequent steps are repeated. If the ejection amount is too small, step S54 becomes NO. Therefore, in step S56, it is checked whether proper coating is possible by setting the robot to the minimum speed. Step S60 if possible
Then, the robot speed is lowered by one step and step S42 and subsequent steps are repeated. When step S60 or S64 is repeated until step S52 becomes yes, the flow rate adjusting valve 2
Since the adjustment process is 0, steps S26 and thereafter in FIG. 5 are executed. There are times when the discharge rate is still insufficient, no matter how slow the robot is. This occurs when the discharge gun 24 or the like is clogged. At this time, since step S56 is NO, an abnormality is displayed in step S62. In the present embodiment, the predetermined discharge amount is larger than the allowable minimum amount QMIN and smaller than the maximum allowable amount QMAX, and the process of step S14 or step S22 is executed until both step S10 and step S18 in FIG. 5 become YES. As a result, the predetermined discharge amount QMIN to QMAX is adjusted to a predetermined adjustment range Δ.
Variable capacity pump 1 so that QV is within the range
The ability of 2 is adjusted. Therefore, the programs that are involved in the execution of these processes and the C that operates based on the programs
It can be seen that the control device H is constituted by the PU 48, the ROM 52 storing the same program, and the like.

After the above processing is completed, step S2
6 and step S30 until both are no, step S
Since the process of S28 or S32 is executed, the discharge amount Q is the predetermined discharge amount QM after the end of the pump capacity.
The control for adjusting the flow rate adjusting valve 20 so that it becomes IN to QMAX is executed. The control device H is configured by the ROM 52 for storing the program and the program involved in the execution of this process, the CPU 48 operated by the program, the solenoid valve 40, and the like. In the present embodiment, the pump capacity is changed if it can be dealt with by adjusting the pump capacity first, and the robot speed is also changed if the pump capacity cannot be adjusted, so that the range of correspondence is wide and the frequency of occurrence of anomalies is kept low. . Further, after being roughly adjusted by the pump capacity and the robot speed, the discharge amount is finely adjusted by the flow rate adjusting valve 20. Therefore, the accuracy of adjusting the discharge amount is significantly improved. Further, in this embodiment, since the flow rate adjusting valve 20 in which precipitation does not easily occur is used and a large amount of liquid moving body is sent out by using the bypass passage, pump clogging is less likely to occur.

[0021]

According to the present invention, a bypass path is added,
Since a flow rate adjusting device is added here, it is possible to use a large capacity pump that does not easily get clogged as a pump, and with a large capacity pump it is difficult to adjust the discharge amount with a fine texture. Fine adjustment is possible. For this reason, it is possible to obtain a discharge device that is hard to be clogged and has excellent discharge amount adjusting ability, and the practical effect is extremely high.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing the concept of the present invention.

FIG. 2 is a diagram schematically showing a system according to an embodiment.

FIG. 3 is an enlarged view of a flow rate adjusting device.

FIG. 4 is an enlarged view of another adjusting device.

FIG. 5 is a diagram showing a control procedure.

FIG. 6 is a diagram showing a control procedure.

FIG. 7 is a diagram illustrating the content of control.

[Explanation of symbols]

 A; Tank; 8 B; Circulation path; 10, 14, 16, 22 C; Bypass path; 18 D; Flow rate adjusting device; 20 E; Variable capacity pump; 12 F; Discharger; 24 G; Discharge amount detection device 26 H; control device; 48, 50, 52 pump capacity adjustment; S10, S14, S18, S22 flow rate adjustment device adjustment; S26, S28, S30, S32

Front page continued (72) Inventor Naoharu Wada 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor: Isamu Yamamoto 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Yoji Nakamura 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A discharge device for discharging the fluid from the discharger by circulating a liquid moving body that easily precipitates in a circulation path provided between the tank and the discharger by a variable capacity pump. A device for detecting the amount of fluid discharged from the dispenser, a bypass passage for bypassing the dispenser, a flow rate adjusting device for adjusting the flow rate of the bypass passage, and an amount detected by the discharge amount detecting device. The capacity of the variable capacity pump is adjusted so as to be within a range in which a predetermined adjustment range is increased or decreased to a predetermined discharge amount, and then the flow rate adjusting device is adjusted so that the amount detected by the discharge amount detection device becomes the predetermined discharge amount. And a control device for adjusting the discharge amount.