JPH0551384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a control device for a self-hardening sand mixer for obtaining self-hardening kneaded sand that is a material for cast iron molds.

More specifically, the present invention relates to a control device for a self-hardening sand mixer that is capable of kneading predetermined amounts of sand, resin, and hardening agent to obtain kneaded sand of a desired weight.

The present invention allows the weight of the kneaded sand to be variably set,
Since the optimal weight of resin and curing agent are automatically mixed in, molds of different sizes and types can be manufactured efficiently while preventing the generation of waste sand.

[Prior art] Conventionally, when producing mixed sand for cast iron molds using a mixer, the opening time of the shutter of the hopper, which is the sand outlet opening in the mixer, is set using a timer relay, and the weight of the mixed sand is determined. Was. Furthermore, the weight of the resin and curing agent mixed into the mixer was determined by setting the opening time of a solenoid valve provided on a pipe introduced into the mixer using a timer relay.

Therefore, it was necessary to determine the desired sand weight for each different size of cast iron mold, calculate the shutter and opening time corresponding to this sand weight, and set the timer relay at that time. Moreover, if the sand weight differs, it is necessary to calculate the corresponding mixing amounts of resin and curing agent, and set a timer relay to control each solenoid valve accordingly. Therefore, in order to create a wide variety of cast iron molds,
It was quite difficult to do unless I had to make complicated settings for each timer relay one by one.

Moreover, if the kneaded sand is made to be larger than the weight of the mold, the amount of wasted sand will inevitably increase. Due to these causes, the manufacturing efficiency of the mold was extremely poor.

[Problems to be Solved by the Invention] The present invention has been made to improve these conventional drawbacks, and allows the weight of sand to be arbitrarily set, and the mixing ratio of resin and curing agent to be adjusted accordingly. The purpose of this invention is to automatically set the required weight of kneaded sand in a variable and automatic manner, thereby efficiently producing kneaded sand for molds.

[Means for Solving the Problems] The present invention is a self-hardening sand mixer control device for controlling a supply device that controls the introduction of sand, resin, and hardening agent into the mixer, which comprises: a weight setting device for setting the weight of sand to be introduced into the sand; and a weight setting device for setting the sand weight to be introduced into the sand, and a weight setting device for setting the sand weight to be introduced into the sand, and a weight setting device for setting the sand weight to be introduced into the sand. The operation time of the sand supply device, the resin supply device, and the curing agent supply device are calculated, and the operation time of the sand supply device and the resin supply device are made the same. a calculation device that calculates the capacity of the variable displacement pump that supplies the sand; and a calculation device that calculates the capacity of the variable displacement pump that supplies the sand; and a calculation device that sets the capacity of the variable displacement pump based on the time and capacity calculated by the calculation device; This is a mixer control device for self-hardening sand, comprising: a control section that operates the supply device synchronously and also operates the curing agent supply device.

The weight setting device can input and store one or more set weights. If multiple weight settings are made, the weight can be selected.

The above-mentioned supply device refers to a shutter, a solenoid valve, which controls the amount of sand, resin, and curing agent introduced into the mixer, an air cylinder, a hydraulic cylinder, which controls the shutter, etc., and a switching solenoid valve, which controls them. . The arithmetic device can be configured not only by a digital computer but also by an analog arithmetic circuit. The calculation device determines the opening time, which is the supply time of the supply device such as the shutter or solenoid valve, and the capacity of the variable displacement pump, according to the set sand weight. The control unit is a circuit device including a relay, a transistor, etc. that generates a signal for operating the solenoid valve, switching solenoid valve, etc. of the supply device.

Further, the calculation means may be provided with a temperature detection device for detecting the temperature of the sand, and the mixed weight of the curing agent may be corrected based on the sand temperature detected by this device. In this way, constant curing speed and degree of curing can be obtained regardless of changes in outside temperature, and the quality of the mold can be improved.

[Operation] Based on the sand weight set by the weight setting device, the calculation device calculates the required weight of the resin and curing agent, and also adjusts the supply time and variable capacity of the supply device according to these weights. Calculate the capacity of the device. The control unit controls the drive of the capacity setting of the variable displacement pump and, based on this calculated time,
The drive of the sand and resin supply devices is synchronously controlled, and the drive of the curing agent supply device is also controlled. Due to this action, it is possible to simultaneously and evenly introduce sand and resin, and to obtain optimal kneaded sand of any weight that is more homogeneously mixed.

[Examples] Hereinafter, the present invention will be described in detail based on specific examples. FIG. 1 is a block diagram showing the configuration of a self-hardening sand mixer device controlled by a mixer control device according to a specific embodiment of the present invention.

Sand is stored in a sand tank 72. The sand tank 2 is connected to a hopper 4 which opens into a mixer 6. A shutter 10, which is a sand supply device, is slidably driven in the hopper 4. The shutter 10 has an opening 100 in a part thereof, and when the opening 100 is slid into the hopper 4, the sand in the sand tank 2 falls into the mixer 6.

The shutter 10 is connected to a piston 102 of an air cylinder 12.
is actuated by air pressure introduced and controlled by a switching solenoid valve 14. The air pressure is the air pressure source 16
generated by. The switching solenoid valve 14 has a solenoid 140 and a return spring 142. By energizing the solenoid 140, the switching solenoid valve 14 is actuated, and the piston 102 is actuated.
The opening 100 of the shutter 10 can be placed inside the hopper 4.

On the other hand, the mixer 6 has a pipe 2 that leads the resin.
0 is open, and the pipe 20 is provided with a solenoid valve 22 which is a supply device for controlling discharge of resin.

A variable displacement pump 200 and a motor 202 that drives it are connected to the pipe 20.
A pump 200 pumps up resin from a resin tank 204 and pumps it to a mixer. The solenoid valve 22 has a solenoid 220, and when it is energized, the solenoid valve is opened.

Further, a pipe 30 for guiding the curing agent is open in the mixer 6, and the pipe 30 is provided with an electromagnetic valve 32, which is a supply device for controlling discharge of the curing agent. A variable displacement pump 3 is connected to the pipe 30.
00 is connected to a motor 302 that drives it, and the pump 300 is connected to a hardening agent tank 304.
The curing agent is pumped up and pumped into the mixer. The solenoid valve 32 has a solenoid 320, and when it is energized, the solenoid valve 32 is brought into an open state.

On the other hand, the mixer 6 is provided with a discharge port 60 at its bottom for discharging the mixed sand, and when the opening/closing lid 62 is operated, the mixed sand falls into the mold manufacturing frame. A link 64 is operatively connected to the opening/closing lid 62, and a piston 66 is connected to the link 64. The piston 66 is controlled by air sent to a cylinder 68, and the direction of movement of the cylinder 68 is controlled by a switching solenoid valve 70. The switching solenoid valve 70 is included in a solenoid 700, and when the solenoid 700 is energized, the opening/closing lid 62 is opened. 702 is an air pressure source for controlling the cylinder 68.

Further, a rotary blade 600 for kneading sand is provided in the mixer 6, and this rotary blade 60
0 is driven by motor 602.

FIG. 2 is a block diagram showing the configuration of the apparatus of this embodiment.

The weight setting device includes a data input keyboard 81 included in the control panel 80, a display lid 82 that displays values set by the keyboard 81, and a storage device (RAM) 83 that stores the set values. It has a CPU 84, a BCD input port 85 and a BCD output port 86 for interfacing with these devices. The calculation unit is CPU84
and RAM that stores predetermined programs and constants.
It consists of 83. Furthermore, in this embodiment, a thermistor 87 provided inside the sand tank 2 to detect the temperature of the sand, and an A/D converter 88 for processing the signal output from the thermistor 87 are added to the arithmetic unit. ing.

The control unit includes an output interface 90 connected to the CPU 84 and each solenoid 140, 220, 3.
20, relays R1, R2, R3 and their relay contacts RC1, RC2, RC3,
Transistors Tr1, Tr2, which drive each relay,
Tr3, a reed switch L1a that detects the open state of the shutter 10, a reed switch L1b that detects its closed state, a reed switch L2 that detects the closed state of the solenoid valve 22, a reed switch L3 that detects the closed state of the solenoid valve 32, and their output signals
and an input interface 92 connected to the CPU 84.

The control panel 80 has a sequence controller 800, and the sequence controller 800 controls the supply of electricity to the solenoid 700 and controls the discharge of the kneaded sand.

FIG. 3 is a plan view of the control panel 80. FIG. 4 is a flowchart illustrating the processing of the CPU 84 used in the device of this embodiment. CPU 84 begins execution at step 100. At step 100, an initial set is performed, and the process moves to step 102. Read the data from the keyboard 81 and check the frame weight (sand weight)
Step 108 through step 106
Then, the data is stored in a predetermined address of the RAM 83, and the weight input on the display panel 82 is set in step 110, and the process returns to step 102. In the device of this embodiment, four types of frame weights can be set. Next step
At 120, the set weight is selected, and a selection frame is displayed on the corresponding display panel.

Next, when the start switch is input in step 122, it is confirmed in step 124 that the opening/closing lid 62 is closed using the reed switch L4.
Next, in step 128, it is checked whether the set weight is within the appropriate range, and in step 130, a signal is input from the thermistor 87 and the sand temperature is read. After the normality determination is made, the opening time of the shutter 10 is calculated in step 134. Time t is t=
Obtained at 84M/1000sec. However, M is the sand weight. Next, in step 136, to incorporate the curing agent,
The opening time, which is the supply time of the solenoid valve 32, is calculated. t is t=M×(3.665−0.0666XTP)/10sec
However, TP is the temperature of the sand. Next, the CPU's soft timers C1 and C2 are set to the above-mentioned times, and in step 140, a signal is output to operate the relays R1 and R2. At step 142, the reed switch L1a reads that the shutter 10 is open, and the reed switch L2 reads that the solenoid valve 22 is open.
4, the operating status is displayed on the display panel 82. Next, in step 145, relay R4 is turned on to drive mixer motor 602. Next, in step 146, timer C1 is updated at 0.1 second intervals, and in step 148
Then, measure the predetermined time. When the specified time has passed,
At step 150, relays R1 and R2 are turned off, shutter 10 is closed, and solenoid valve 22 is closed. In this example, the supply time for controlling the mixing of sand and resin was the same, and the mixing ratio of sand to resin was determined by setting the capacity of the variable displacement pump 200.
In step 152, the shutter 10 and the solenoid valve 22 are
After confirming the closed state, in step 154, relay R3 for introducing the curing agent is turned on. After confirming the open state of the electromagnetic valve 32 in step 156, the timer C2 is updated in step 158, and it is determined in step 160 whether a predetermined time has elapsed. When the predetermined time has elapsed, relay R3 is turned off in step 162, solenoid valve 32 is closed, and this is confirmed in step 164. In this way, the curing agent is introduced into the mixer 6 for a predetermined period of time, and the mixing of the curing agent is completed.

Next, in step 166, a time is set in a counter CM that determines the drive time of the mixer motor 602, and after measuring a predetermined time in steps 168 and 170, in step 172, relay R4 is turned off to stop driving the mixer motor 602. let Next, in step 174, the sequence controller 8
00, the PU 84 is made to wait in step 176, and the processing completion signal of the sequence controller 800 is inputted as an interrupt signal. At that time, the process returns to step 102 and the next cycle is processed.

The sequence controller 800 operates the switching solenoid valve 70, drives the air cylinder 68, and
The opening/closing lid 62 is opened and the mixed sand is taken out from the mixer 6. When sand removal is completed, the air cylinder is driven by sequence control and the opening/closing lid 62 is closed.

In the above steps, if the clear key is input in step 122, the process returns to step 102. Also, if the opening/closing lid 62 is open in step 126, the process is cleared in step 202, and the process returns to step 102.
Return to. If the set weight is not within the normal range at step 128, the process is cleared at step 204 and the process returns to step 102. If there is an abnormality in step 132, processing for the thermometer abnormality is performed in step 206. If an abnormality is found in steps 152 and 164, abnormality processing is performed in step 208.

In this example, the amount of hardening agent introduced is determined by detecting the temperature of the sand, so good quality kneaded sand can be obtained regardless of the season, and the mixing amount of hardening agent can be set according to the season. There's no need to.

[Effects of the Invention] Since the device of the present invention has a sand weight setting device, a desired weight of sand can be arbitrarily selected, and generation of invalid sand can be prevented. Furthermore, since it has a calculation device, the amount of resin and curing agent to be introduced can be automatically set. Therefore, there is no need to set separate timers for each, and desired kneaded sand can be obtained simply by setting the sand weight. Furthermore, since the sand and resin are simultaneously and evenly supplied to the mixer, it is possible to mix the sand and resin more uniformly. Therefore, high quality self-hardening sand can be obtained with high efficiency.

[Brief explanation of the drawing]

FIG. 1 is a specific configuration diagram of a mixer device that is controlled by a specific embodiment of the present invention. FIG. 2 is a configuration diagram showing the configuration of a mixer control device for self-hardening sand according to a specific embodiment of the present invention. FIG. 3 is a plan view of a control panel included in the apparatus of the embodiment. FIG. 4 is a flowchart showing the processing of the computer included in the apparatus of the embodiment. 2...Sand tank, 4...Hopper, 6...Mixer, 10...Shutter, 12,68...Air cylinder, 14,70...Switching solenoid valve, 22,3
2...Solenoid valve, 140,220,320,700
... Solenoid, 87 ... Thermistor, L1a,
L1b, L2, L3, L4...Reed switch.

Claims (1)

[Scope of Claims] 1. A mixer control device for self-hardening sand for controlling a supply device that controls the introduction of sand, resin, and hardening agent into the mixer, which sets the weight at which the sand is introduced into the mixer. and a weight setting device that controls the sand supply device and the resin supply device so that the operating time of the sand supply device and the resin supply device are the same based on the sand weight set by the weight setting device. A variable capacity pump that supplies the resin is used to calculate the operating time of the resin supply device and the curing agent supply device, and to make the operating time of the sand supply device and the resin supply device the same. a calculation device that calculates the capacity; and a calculation device that sets the capacity of the variable displacement pump based on the time and capacity calculated by the calculation device, and operates the sand supply device and the resin supply device in synchronization. A control unit for a self-hardening sand mixer, comprising: a controller for controlling the curing agent and operating the curing agent supply device; 2. The calculation device has a temperature detection device that detects the temperature of the sand, and the hardening is performed according to the temperature detected by the temperature detection device and the sand weight set by the weight setting device. The mixer control device for self-hardening sand according to claim 1, characterized in that the time for operating the agent supply device is calculated.