JPH0539821Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in a conveying device for a flask or a mold.

(Prior Art) In order to transfer a plurality of flasks or molds lined up in a ball shape on a conveyance line without impacting them, a cushion cylinder catches the ends of the flasks or molds in the feeding direction, and receives them with a cushion cylinder. A method of transporting a flask or mold is known, in which the other end is pressed by an extrusion cylinder, the flask or mold is sandwiched, and the flask or mold is pushed out by the stroke of the extrusion cylinder. Usually, a pneumatic type is used, and a hydraulic type is usually used as a pick-up cylinder (for example, Japanese Utility Model Publication No. 62-46665
Publication No.).

(Problem that the invention aims to solve) By the way, Japan has four seasons, and the ambient temperature at production sites varies by about -10 to 40 degrees Celsius depending on the season.
Along with this temperature change, the viscosity of the hydraulic oil used in the above-mentioned pick-up cylinder changes drastically.At low temperatures, the hydraulic oil becomes thick and the spring constant of the cylinder becomes large, and at high temperatures, the hydraulic oil The viscosity decreases and the spring constant of the cylinder decreases. As a result, at low temperatures, the flask or mold in the middle of the conveyance line floats up and derails, and at high temperatures, the pick-up cylinder cannot completely eliminate the inertia of the flask or mold during conveyance, causing damage to the mold. Problems such as giving

On the other hand, in conventional pneumatic extrusion cylinders, a large-capacity cylinder is used to extrude a large number of flasks or molds. The pick-up cylinder also had to have a large capacity, which increased costs.

The present invention was developed in view of the above circumstances, and its first purpose is to provide a device that can transport flasks or molds smoothly and without damage, regardless of the environmental temperature. It is to be. A second object of the present invention is to provide an apparatus that does not require increasing the capacity of the pick-up cylinder even when a large number of flasks or molds are transported.

(Means for Solving the Problems) In order to achieve the above object, the present invention adopts an electric servo-type extrusion cylinder in place of the conventional pneumatic extrusion cylinder, and replaces the conventional hydraulic pick-up cylinder with an electric servo-type extrusion cylinder. Instead, an electric servo-type pick-up cylinder is adopted, and the gist of the invention is to operate both cylinders in synchronization when transporting the flask or mold.

That is, the present invention firstly involves sandwiching a cast flask or a group of trolleys for transporting molds from both front and rear sides by an electric servo type extrusion cylinder and an electric servo type pick-up cylinder, and then extending the rod of the extrusion cylinder. A flask or mold conveying device that synchronizes the retraction operation of the rod of the pick-up cylinder and similarly moves the group of carts one by one intermittently, and is connected to the motor of the extrusion cylinder. a first inverter connected to the motor of the receiving cylinder, and a first inverter that exchanges the excitation frequency of the motor based on an excitation frequency command signal;
A second inverter converts the excitation frequency of the motor based on an excitation frequency command signal, and when the rod of the extrusion cylinder is extended, the first inverter converts the excitation frequency of the motor to a predetermined excitation frequency at a preset timing.
In addition to giving a command signal to the inverter, when the rod of the pick-up cylinder is retracted, an excitation frequency that is slightly lower than the excitation frequency given to the first inverter is applied to the second inverter in synchronization with the first inverter. It is characterized by comprising a frequency command means for giving a command signal to the frequency command. Second, in the present invention, a pressure sensor is attached to the rod head of the pick-up cushion cylinder to measure the pressing force when the truck group moves, and when the rod of the pick-up cushion cylinder is retracted, The frequency command means 27 causes the excitation frequency to be increased when the pressure measured by the pressure sensor exceeds a preset range, and to decrease the excitation frequency when the pressure is below a preset range. It is characterized in that a command signal is issued to the second inverter.

(Structure) Hereinafter, the present invention will be described in detail based on examples.

FIG. 1 is a plan view and a control circuit diagram showing an embodiment of the present invention, and FIG. 2 is a cutaway view of the main parts of an extrusion cylinder.

In FIG. 1, on the trolley transport rail 1,
For example, a plurality of carts 2 for transporting flasks, molds, etc. are mounted, and these carts 2 are connected to each other and are movable as a group on the rails 1 via wheels 3. There is. On the outside of the left end of the rail 1, a rail 4 for transporting the cart 2 from another line is laid orthogonally.
A trolley 5 for mounting a trolley is movably mounted on the rail 4 via wheels 6. A rail 7 connectable to the trolley transport rail 1 is provided on the trolley 5, and the trolley 2 sent from another line is placed on the rail via wheels 3. ing.

Also, on the outside of the right end of the trolley transport rail 1,
Rails 11 for transporting the cart 2 to another line are laid orthogonally, and a cart 12 for placing a cart is movably mounted on the rails 11 via wheels 13. A rail 14 connectable to the truck transport rail 1 is provided on the truck 13.

An electric servo push-out cylinder 15 is located on the outside of the trolley loading rail 4 on the extension line of the truck transport rail 1, and an electric servo pick-up cylinder 16 is opposed to the outside of the trolley unloading rail 1. It is provided. As shown in FIG. 2, the extrusion cylinder 15 includes a cylindrical cylinder case 16 and a cylinder case 16.
lids 17 and 18 that close openings at both ends; a motor 19 that is rotatable in forward and reverse directions and that is disposed outside the base end of the cylinder case 16; side lid 18
A cylindrical rod 20 that can slide through the cylinder, a piston 21 fixed to the base end of the rod 20 and slidable inside the cylinder case 16, and a connecting bolt 22 at the tip of the rod 20. A rod head 23 is fixed to the piston 21 through the rod head 23, a ball nut 24 is fixed through the center of the piston 21, and the ball nut 24 is screwed onto the ball nut 24 and loosely inserted into the rod 20, and one end is connected to the cylinder case 16. It consists of a ball screw 26 that passes through the cover 17 on the base end side and is connected to the rotating shaft 25 of the motor 19. The ball screw 26 rotates in the normal direction when the motor 19 is driven to rotate in the normal direction, and the piston 21 rotates in the normal direction. It moves to the right, and the rod 20 is extended. Conversely, when the motor 19 is driven in reverse, the ball screw 26 is rotated in the opposite direction, and the piston 21 moves to the left, causing the rod 20 to rotate in the opposite direction.
is retracted. Note that the rotation speed of the motor 19,
That is, the extension/contraction distance of the rod 20 can be arbitrarily controlled by an encoder attached to the motor 19 and an electromagnetic brake (not shown), and can be controlled by a position control means (not shown) connected to these devices. The rod 20 is designed to stop at a preset position in response to this command.

Further, the motor 19 is connected to a first inverter 27 that can arbitrarily convert its excitation frequency, and the first inverter 27 is further connected to a frequency command means 28. And the above rod 20
When the motor 19 is extended, a predetermined excitation frequency is applied to the motor 19 at a preset timing based on a command signal from the frequency command means 28, thereby increasing the rotational speed of the motor 19 (rotations per unit time). number) has been changed, and the above rod 20
The elongation speed is controlled. The configuration of the pick-up cushion cylinder 16 is the same as that of the extrusion cylinder 15, so a description thereof will be omitted. The motor 2 of the pick-up cylinder 16
Similarly to the motor 19 of the extrusion cylinder 15, the motor 9 is also connected to a position control means (not shown), and the rod 30 of the cylinder 16 is stopped at an arbitrary position in response to a command from the position control means.
Further, the motor 29 is connected to a second inverter 31 whose excitation frequency can be arbitrarily changed, and the second inverter 31 is further connected to the frequency command means 28. When the rod 30 is retracted, the excitation frequency given to the motor 19 of the extrusion cylinder 15 from the frequency command means 28 (more precisely, the excitation frequency given to the motor 19 of the extrusion cylinder 15 is At the same timing, an excitation frequency slightly lower than the excitation frequency (subtracting the slip frequency) is applied to the motor 29, thereby converting the rotational speed of the motor 29 and controlling the retraction speed of the rod 30. It has been done. That is, the extrusion cylinder 15
The extension synchronous speed of the rod 20 of the cylinder 16 is designed to be slightly higher than the retraction synchronous speed of the rod 29 of the receiving cylinder 16, and both rods 2
The extension and retraction operations of 0.0 and 30 are controlled synchronously.

Further, the motor 29 of the pick-up cylinder 16 is electrically connected to a resistor, a heater, a power generation lamp, etc. (not shown), and the rod 3 of the cylinder 16 is
It is configured to consume the electrical energy generated when 0 is retracted.

Furthermore, a pressure sensor 33 is attached to the front surface of the rod head 32 in the cylinder 16 to measure the pressing force when the two groups of carts move.
The rod 3 of the cylinder 16 is electrically connected to the rod 3 of the cylinder 16.
0, if the pressure measured by the pressure sensor 33 deviates from a preset pressure range, the second inverter 31 is activated based on the command signal from the frequency command means 28. Then, the excitation frequency applied to the motor 29 of the cylinder 16 is controlled to increase or decrease.
The retracting speed of the rod 30 of No. 6 is adjusted.

(Operation) Next, the steps of loading, transporting, and discharging the trolley using the apparatus configured as described above will be explained. As shown in FIG. 1, the rod 20 of the push-out cylinder 15 and the rod 30 of the pick-up cylinder 16 were retracted, and the cart 12 on the cart carrying rail 11 was connected to the outer right end of the cart transporting rail 1. In this state, first, the motor 29 of the pick-up cylinder 16 is driven in normal rotation to rotate the rod 30.
Activate the extension. When the rod head 32 comes into contact with the leading one of the two groups of carts placed on the rail 1 for carrying out carts, the rotation of the motor 29 is stopped and the extending operation of the rod 30 is stopped. At this time, DC electricity is applied to the motor 29 to lock the rod 30 so that it does not retract.

Second, the trolley 5 for mounting a trolley on the rail 4 for transporting a trolley is connected to the outer left end of the rail 1 for transporting a trolley.
Thirdly, when the motor 19 of the extrusion cylinder 15 is driven in normal rotation to extend the rod 20, the rod head 23 pushes the flask or mold transporting trolley 2 placed on the trolley mounting trolley 5, and The trolley 2 comes into contact with the last one of the two groups of trolleys on the rail 1 for transporting the trolley. That is, a plurality of carriages 2 are sandwiched between the rod head 23 of the extrusion cylinder 15 and the rod head 32 of the pick-up cylinder 16 and are connected in a ball-like manner. In this state, the drive of the motor 19 of the extrusion cylinder 15 is temporarily stopped.

Fourth, the motor 19 of the extrusion cylinder 15 is driven to rotate in the forward direction, and the motor 29 of the pick-up cylinder 16 is driven in the reverse direction. At this time, a predetermined excitation frequency is applied to both motors 19 and 29 at a preset timing. As a result, from the difference between the synchronous speed of extension of the rod 20 of the extrusion cylinder 15 and the synchronous speed of contraction of the rod 30 of the pick-up cylinder 16, the rod 2 of the extrusion cylinder 15 is
0 picks up cushion cylinder 1 via two groups of bogies.
The rod 30 of the cushion cylinder 16 is extended by pushing it, and the speed of the extension changes over time according to a preset speed pattern (acceleration - constant speed - deceleration), and the rod 30 of the receiving cushion cylinder 16 is also moved in synchronization with this. Retraction works. In addition, the pick-up cushion cylinder 1
The motor 29 of 6 is connected to the rod 30 of the cylinder 16.
is pushed by the rod 20 of the extrusion cylinder 15, so it rotates at a speed that exceeds its rotational synchronous speed, and at this time electrical energy is generated, but this energy is consumed and absorbed by resistors, heaters, power generating lamps, etc. (not shown). be done.

Due to the operation of the rods 20 and 30 as described above,
The second group of bogies, with their front and rear ends sandwiched between the rod heads 23 and 32, move one stroke toward the right in Fig. 1 on the bogie transport rail 1 in a predetermined speed pattern (acceleration - constant speed - deceleration). , the first cart 2 is placed on the cart 12 on the rail 11 for carrying out the cart. During the movement of the second group of trucks, if the pressure applied to the rod head 32 of the pick-up cylinder 16 exceeds a preset pressure range (for example, the load on the truck 2 is too light and the rod 20 of the push-out cylinder 16 If the pressing force is too strong), the frequency command means 28 issues a command signal to the second inverter 31 based on the signal from the pressure sensor 33 attached to the rod head 32,
The excitation frequency of the motor 29 of the pick-up cylinder 16 is increased.

This increases the rotational synchronous speed of the motor 29, that is, the retraction synchronous speed of the rod 30 of the cylinder 16. On the other hand, if the pressure applied to the rod head 32 is below a preset pressure range (for example, if the load on the truck 2 is too heavy and the moving speed of the group of trucks 2 cannot be increased), the rod of the cylinder 16 is 30 contraction synchronization speed becomes slower. In this way, the cushion cylinder 16
The pressure on the rod head 32 is maintained within a predetermined range.

When the movement of the second group of carts is completed in this way, the synchronized rotation mode of both the motors 19 and 29 is released, and the fifth pumping cylinder 16
The motor 29 is further driven in the reverse direction to retract the rod 30 slightly, thereby separating the rod head 32 and the leading truck 2.
Leave some space between them. Sixth, after retracting the rod 20 of the extrusion cylinder 15 to return it to its original state, a return device (not shown) is activated to leave the leading truck 2 and move the other 2 groups of trucks slightly backward.
This will leave a slight gap. Seventhly, the cart 12 on the cart carrying rail 11 is moved to carry out the leading cart 2 to another line, and a new cart 2 is placed between the last cart 2 and the extrusion cylinder 15 from another line. will be brought in. Eighth, rail 11 for carrying out the trolley
The upper empty trolley 12 is connected to the outer right end of the trolley transport rail 1.

The above steps constitute one cycle, and the same cycle is repeated thereafter, and the flasks or the trolleys 2 for transporting the flasks are brought in, transported, and taken out one by one.

(Effects of the invention) In the present invention as described above, an electric servo-type cylinder is used as the pick-up cylinder, so it is less affected by environmental temperature than a hydraulic cylinder. Therefore, the same cushioning effect can be obtained regardless of the season, and the flask or mold can be transported smoothly and without damage.

In addition, in the present invention, an electric servo-type extrusion cylinder is used, and the elongation speed of the cylinder rod is controlled in three stages: acceleration, constant speed, and deceleration, thereby controlling the conveyance speed of the flask or mold. At the same time, since the rod and the rod of the pick-up cylinder are moved synchronously with the flask or mold in between, even when a large number of flasks or molds are transported, the flask group or mold group can be moved at high speed. There is no inertial movement, the pressure applied to the pick-up cylinder is reduced, and the capacity of the cylinder can be reduced. In other words, costs will be reduced.

In the embodiment, a pressure sensor was attached to the rod head of the pickup cylinder to maintain the pressure applied to the rod head within a predetermined range. Attachment of the sensor may be omitted.

[Brief explanation of the drawing]

FIG. 1 is a plan view and a control circuit diagram showing an embodiment of the present invention, and FIG. 2 is a cutaway view of the main parts of an extrusion cylinder. 2...Dolly, 15...Electric servo type extrusion cylinder, 16...Electric servo type pickup cylinder, 19, 29...Motor, 20, 30...Rod, 27...First inverter, 28...Frequency Command means, 31... second inverter, 32... rod head, 33... pressure sensor.

Claims (1)

[Claims for Utility Model Registration] 1. Two groups of carts for transporting flasks or molds are sandwiched from both front and rear sides by an electric servo type extrusion cylinder 15 and an electric servo type pick-up cylinder 16, and the extrusion cylinder 15 is rod 2
0 extension operation and the pick-up cylinder 16
The retraction operation of the rod 30 is performed in synchronization with the retraction operation of the rod 30,
This is a flask or mold conveying device that intermittently moves the two groups of carts one by one, and is connected to the motor 19 of the extrusion cylinder 15, and controls the excitation frequency of the motor 19 based on an excitation frequency command signal. a first inverter 27 to be replaced; a second inverter 31 connected to the motor 29 of the pickup cylinder 16 and converting the excitation frequency of the motor 29 based on an excitation frequency command signal; and a rod of the extrusion cylinder 15. 20
When the rod 30 of the pick-up cylinder 16 is retracted, a predetermined excitation frequency is given as a command signal to the first inverter 27 at a preset timing. A flask or mold conveying device characterized by comprising: frequency command means 28 which synchronizes with the first inverter 27 and gives an excitation frequency slightly lower than the given excitation frequency to the second inverter 31 as a command signal. . 2. A pressure sensor 33 is attached to the rod head 32 of the pick-up cushion cylinder 16 to measure the pressing force when the two groups of carts move, and when the rod 30 of the pick-up cushion cylinder 16 is retracted, The frequency command means 28 increases the excitation frequency when the pressure measured by the pressure sensor 33 exceeds a preset range, and decreases the excitation frequency when the pressure falls below a preset range. 2. The flask or mold conveying device according to claim 1, wherein a command signal is transmitted from said second inverter 31 to said second inverter 31.