JP2020151738A - Method and device for detecting looseness of rack shaft for vertical injection - Google Patents

Abstract

To provide a method and a device for detecting the looseness of a rack shaft for vertical injection capable of easily and efficiently detecting the looseness of a rack shaft fixed to a coupling of an injection device in a vertical die cast machine.SOLUTION: A method for detecting the looseness of a rack shaft for vertical injection according to the present invention comprises: a step where a lifting limit position when an injection sleeve 2 is lifted and a retreat limit position when it is injection-retreated are detected by a position detection part 20 fitted to a coupling 12 of an injection device 1 of a vertical die cast machine and detecting the movement position of a rack shaft 22 moving forward and backward together with a plunger 14; and a step where a lifting limit set value in which the lifting limit position is predetermined and a retreat limit set value in which the retreat limit position is predetermined are compared, and, when the lifting limit set value or the retreat limit set value is out of an allowable range, it is determined that the rack shaft 22 fitted to the coupling 12 has looseness.SELECTED DRAWING: Figure 1

Description

The present invention is a vertical mold capable of detecting looseness of a fixing portion for fixing a rack shaft to a coupling, which is a component of a position detection unit for measuring a speed displacement position of a plunger provided in an injection device of a vertical die casting machine. The present invention relates to a method for detecting looseness of an injection rack shaft and its device.

FIG. 4 is an operation explanatory view of an injection device of a vertical die casting machine. In the injection device 1 of the vertical die casting machine, the injection sleeve (hereinafter, may be simply referred to as a sleeve) 2, the sleeve frame 3, and the injection cylinder 4 are integrated and upright in the vertical direction. Tilt by ~ 20 degrees to stop. Then, the molten metal is poured into the injection sleeve 2 by the toribe 6. After that, it returns to the original upright state by returning to tilt (returning from the tilted state to the original upright state). Next, after setting the hydraulic oil pressures in the rod side chamber and the head side chamber of the injection cylinder 4 to an offload (no load) state, the sleeve frame 3 is gently raised, and the upper end of the injection sleeve 2 is fixed to the mold 7. The docking work is completed by being in close contact with the mounting part drilled on the lower surface of the sleeve (sleeve rising limit state). After that, the injection cylinder 4 is operated to inject and fill the molten metal in the injection sleeve 2 into the mold cavity 8.

Such an injection device is provided with a stroke sensor for detecting the injection stroke position or a position sensor (linear encoder, ultrasonic displacement, laser beam displacement, etc.) for measuring the advancing / retreating movement distance of the piston rod. There is a device that manages the operation of the injection device (for example, disclosed in Patent Documents 1 and 2).
As an example of a specific configuration of the position detection unit such as the injection stroke, there is one provided with a rack shaft and a pinion meshing structure. 5A and 5B are explanatory views of a position detection unit, FIG. 5A is a right side view of FIG. 4, and FIG. 52 is a view taken along the line BB of FIG. As shown in the figure, the position detection unit 20 includes a rack shaft 22, a pinion 30, and an encoder 40. The upper end side of the rack shaft 22 is fixed by the coupling 12 and the nut 13 (fixed portion) of the injection device, and is configured to be movable back and forth together with the plunger 14.
The rack shaft 22 and the fixed portion are exposed to a solution such as a mold release agent during work and deteriorate over time due to peeling, corrosion, settling, etc., and troubles such as tooth surface wear, dropout, and breakage of the rack shaft 22 and pinion 30 occur. Occurs.
For this reason, it was necessary to check the appearance and replace parts regularly to prevent such problems, but since the installation location is in the pit and there is no work floor, artificial work is performed. This is not preferable because it is troublesome and the down time of the device becomes long. Further, conventionally, there has been no means for automatically detecting looseness of a fixing portion for fixing such a rack shaft to a coupling.

Japanese Unexamined Patent Publication No. 2003-340558 Japanese Unexamined Patent Publication No. 10-34308

The problem to be solved by the present invention is a vertical injection rack shaft capable of easily and efficiently detecting looseness of a rack shaft fixed to a coupling of an injection device of a vertical die casting machine in view of the above-mentioned problems of the prior art. It is an object of the present invention to provide a method for detecting looseness and a device thereof.

In the present invention, as a first means for solving the above problems, an injection sleeve is provided by a position detecting unit that is attached to a coupling of an injection device of a vertical die casting machine and detects a moving position of a rack shaft that moves forward and backward together with a plunger. The process of detecting the ascending limit position when the injection is raised and the retreating limit position when the injection is retracted,
When the ascending limit position is compared with the predetermined ascending limit set value and the retreating limit position is out of the allowable range of the ascending limit set value or the retreating limit set value, the said The process of determining that the rack shaft attached to the coupling is loose, and
It is an object of the present invention to provide a method for detecting looseness of a vertical injection rack shaft, which comprises the above.
According to the first means, the looseness of the fixed portion of the rack shaft can be determined from the detected values of the ascending limit position and the retracting limit position of the injection sleeve without the visual inspection of the operator.

In the present invention, as a second means for solving the above-mentioned problems, in the first means, the ascending limit position and the retreating limit position detected by initializing the rack shaft to the coupling are set as the ascending limit. It is an object of the present invention to provide a method for detecting looseness of a vertical injection rack shaft, which comprises setting a set value and the retracted limit set value.
According to the second means, a set value (master value) that can be compared with the measured value can be obtained as a criterion for determining the looseness of the rack shaft.

According to the present invention, as a third means for solving the above problems, in the first or second means, the upper end side of the rack shaft is inserted into the perforation of the coupling, and a nut is screwed into the tip. And fix it to the coupling
When the ascending limit position is outside the permissible range of the ascending limit set value, the control unit determines that the upper surface side of the coupling is loose, and when the retreating limit position is outside the permissible range of the retreating limit set value. The present invention provides a method for detecting looseness of a vertical injection rack shaft, which is characterized by determining looseness on the lower surface side of the coupling.
According to the third means, the loosened portion of the fixing portion for fixing the rack shaft to the coupling can be specifically specified and grasped.

In the present invention, as a fourth means for solving the above problems, a rack shaft whose upper end side is fixed to a coupling along the advancing / retreating direction of the injection sleeve of the injection device of the vertical die casting machine and the movement of the rack shaft. A position detection unit that has an encoder that measures the distance and detects the movement position of the rack axis,
Based on the ascending limit position when the injection sleeve is raised and the value measured by the position detection unit of the retreating limit position when the injection sleeve is retracted, the ascending limit setting value in which the ascending limit position is predetermined and the above-mentioned A control unit that compares the retractable limit position with a predetermined retractable limit set value and determines that the rack shaft attached to the coupling is loose when the retractable limit set value or the retractable limit set value is out of the allowable range. When,
It is an object of the present invention to provide a looseness detecting device for a vertical injection rack shaft, which is characterized by having.
According to the fourth means, the looseness of the fixed portion of the rack shaft can be determined from the detected values of the ascending limit position and the retracting limit position of the injection sleeve without visual inspection by the operator.

According to the present invention, the looseness of the fixed portion of the rack shaft can be determined from the detected values of the ascending limit position and the retracting limit position of the injection sleeve without the visual inspection of the operator. In addition, the maintenance time can be predicted or managed from the detected value of looseness.

It is a block diagram of the looseness detection device of the rack shaft for vertical injection of this invention. This is the processing flow of the initial setting mode. This is the processing flow of the detection mode. It is operation explanatory drawing of the injection device of the vertical die casting machine. It is explanatory drawing of the position detection part.

A method for detecting looseness of a vertical injection rack shaft of the present invention and an embodiment of the apparatus thereof will be described in detail below with reference to the drawings.
[Rack shaft loosening detection device 10 for vertical injection]
FIG. 1 is a schematic configuration diagram of looseness detection of the vertical injection rack shaft of the present invention, (1) is a side sectional view of the rack shaft in the retracted limit position, and (2) is a side surface of the rack shaft in the ascending limit position. The cross-sectional view, (3) is an enlarged view of part A of (2), (4) is an explanatory view when a gap is generated on the upper surface side of the coupling, and (5) is a gap on the lower surface side of the coupling. It is explanatory drawing at the time of occurrence. As shown in the figure, the looseness detection device 10 for the vertical injection rack shaft of the present invention mainly includes a position detection unit 20 and a control unit 50. The vertical injection rack shaft of the present invention (hereinafter, may be simply referred to as a rack shaft) is a component of a position detection unit that is attached to a coupling of an injection device of a vertical die casting machine to measure a speed displacement position of a plunger. Refers to the rack shaft.

[Position detection unit 20]
The position detection unit 20 has a rack shaft 22, a pinion 30, and an encoder 40.
The upper end side of the rack shaft 22 is attached to the coupling 12, and the lower end thereof is penetrated into the columnar upper and lower support portions 23 and 24 so that the rack shaft 22 can move forward and backward in the vertical direction, and the side surface of the central portion is cross-sectional direction. It is a round rack with teeth cut. Both the upper and lower support portions 23 and 24 are fixed to the side surface of the injection cylinder 4. A limit switch 26 is provided below the lower support portion 24. The limit switch 26 is a sensor switch that detects the retreat limit position, and can detect the retreat limit position when it comes into contact with the lower end of the rack shaft 22 during injection retreat. This limit switch 26 is used in the initial setting mode described later.
The upper end of the rack shaft 22 is formed to have a diameter smaller than that of the main body, and the tip portion is threaded. Then, using the fixing portion consisting of the nut 13 and the washer 15, the washer 15 through which the small diameter portion penetrates is fitted, and then the small diameter portion is penetrated from the lower surface side to the upper surface side in the perforation of the coupling 12, and the tip protruding from the hole. A nut 13 is screwed into the male screw portion of the above and fixed to the coupling 12 (see FIG. 1 (3)).
The pinion 30 is provided between the upper and lower support portions 23 and 24 at a position facing the gear cutting of the rack shaft 22. The pinion 30 is a gear that rotates by engaging with the gear cut portion of the rack shaft 22, and is connected to the encoder 40 via the pinion shaft 32.

The encoder 40 measures the rotational position of the pinion 30, converts it into an electric signal, and outputs it as position information from the moving distance. The output value of the encoder 40 is the advance / retreat position information of the rack shaft 22, in other words, the plunger 14.
In the position detection unit 20 having such a configuration, the position where the integrated injection sleeve 2, the sleeve frame 3, and the injection cylinder 4 return to the original upright state when the injection sleeve 4 is tilted back is the retreat limit position (FIG. 1 (1)). (Refer to), when the hydraulic oil pressures in the rod side chamber and head side chamber of the injection cylinder 4 are set to the offload (no load) state and the sleeve frame 3 is gently raised, the rack shaft 22 also rises as the plunger 14 rises. To rise. Then, the upper end of the injection sleeve 2 is brought into close contact with the mounting portion formed on the lower surface of the fixed mold 7 to complete the docking operation (sleeve rising limit position) (see FIGS. 1 (2) and 5 (1)).
The movement distance of the rack shaft 22 from the retracted limit position to the sleeve rising limit position is measured by the encoder 40.
Further, the movement distance of the rack axis from the sleeve ascending limit position to the injection retreating limit position is measured by the encoder 40 (see FIG. 1 (1)).
From these two moving distances, the sleeve rising limit position and the injection backward limit position can be detected.

[Control unit 50]
The control unit 50 has program software that is electrically connected to the position detection unit 20 so that the measured value of the position detection unit 20 can be received, and performs the following setting or control operation.
When the rack shaft 22 is first attached to the coupling 12 in advance, the control unit 50 loosens the nut 13 of the fixing portion after repair / maintenance, wear of the gear cut of the rack shaft 22 or the pinion 30, the coupling 12 or The washer 15 is not corroded, and the sleeve ascending limit position when the sleeve is raised in a cold state (when the device is not operating) is set as the ascending limit setting value, and then the injection retreating limit position when the injection is retracted is set as the retracting limit. It is a set value. Allowable ranges for loosening of the nut 13, wear of the gear cutting, etc. are set in advance for the rising limit set value and the retracting limit set value. After that, the control unit 50 allows the position detection unit 20 to compare the ascending limit position when the injection sleeve 2 is raised with the previously obtained ascending limit set value when the device is not operating in the cold state. It is determined whether or not it is within the range. In addition, the detection value of the retreat limit position when the injection is retracted is compared with the retreat limit set value obtained in advance to determine whether or not it is within the allowable range.
The control unit 50 may be electrically connected to an alarm unit (not shown) so as to issue an alarm when the measured value is out of the permissible range.

[Method of detecting looseness of rack shaft for vertical injection]
The method for detecting looseness of the vertical injection rack shaft of the present invention according to the above configuration will be described below.

[Initial setting mode]
FIG. 2 is a processing flow of the initial setting mode.
When the rack shaft 22 is attached to the coupling 12 in advance (at the time of initial installation), after repair / maintenance, the nut of the fixing portion is loosened, the gear cutting of the rack shaft 22 or the pinion 30 is worn, and the coupling 12 or the washer 15 is used. Determine the set value (master value) that can be compared with the measured value when there is no corrosion and when it is cold (the device is not operating).
The injection sleeve 2 of the injection device is raised from the retracted limit position (step 1).
It is determined whether or not the upper end portion of the injection sleeve 2 is brought into close contact with the mounting portion formed on the lower surface of the fixed mold 7 and docked (step 2).
If Yes, the value detected by the position detection unit (moving distance from the backward limit position to the ascending limit position) is stored as the ascending limit set value of the injection sleeve 2 (step 3). If No, the process is performed until docking in step 1.
Subsequently, the injection sleeve 2 is ejected and retracted from the ascending limit position (step 4).
It is determined whether or not the injection sleeve 2 has retreated to the injection retreat limit (step 5). This determination can be determined by using the limit switch 26 to determine the retracted limit position when the rear ends of the rack shaft 22 come into contact with each other.
If Yes, the value detected by the position detection unit (moving distance from the ascending limit position to the retreating limit position) is stored as the retreating limit setting value (step 6). If No, the process is performed in step 4 until the setback limit is reached.
Through the above steps, a set value (master value) that can be compared with the measured value can be obtained as a criterion for determining the looseness of the rack shaft 22.

[Detection mode]
If the injection device is operated for a long time, the rack shaft, the coupling, and the fixing part may be corroded by being exposed to a solution such as a mold release agent, or the nut of the fixing part may be loosened, resulting in deterioration over time. The detection mode is a mode performed outside the normal operating hours to detect looseness of the rack axle. FIG. 3 is a processing flow of the detection mode. The detection mode is performed in a cold state after the initial setting mode has been performed, after a predetermined operating time has elapsed.
The injection sleeve 2 of the injection device is raised from the retracted limit position (step 10).
It is determined whether or not the upper end portion of the injection sleeve 2 is brought into close contact with the mounting portion formed on the lower surface of the fixed mold 7 and docked (step 20).
If Yes, the value detected by the position detection unit is set as the ascending limit position of the injection sleeve 2, and the predetermined ascending limit set value is compared (step 30). If No, the process is performed until docking in step 1.
It is determined whether or not the values compared in step 30 are within the permissible range (step 40).
When the ascending limit position is not within the permissible range (No), it can be determined that a gap is formed on the upper surface side of the coupling 12 (step 50). More specifically, as shown in FIG. 1 (4), it is considered that the upper surface side of the coupling 12 is corroded and the nut 13 of the fixing portion is loosened. At this time, the rack shaft 22 does not rattle in the vertical direction in the perforation of the coupling 12, and is fixed with a gap on the upper surface side of the coupling due to oil or the like. In this case, the ascending limit position is a value smaller than the ascending limit set value by the amount of the generated gap, and it can be determined that the gap is on the upper surface side of the coupling 12.
When the ascending limit position is within the allowable range (Yes), the injection sleeve is subsequently ejected and retracted from the ascending limit position (step 60).
It is determined whether or not the injection sleeve 2 has retreated to the injection retreat limit (step 70).
If Yes, the value detected by the position detection unit is set as the backward limit position, and the predetermined backward limit set value is compared (step 80). If No, the process is performed in step 60 until the setback limit is reached.
It is determined whether or not the values compared in step 80 are within the permissible range (step 90).
When the retreat limit position is not within the permissible range (No), it can be determined that a gap is formed on the lower surface side of the coupling 12 (step 100). More specifically, as shown in FIG. 1 (5), it is considered that the lower surface side of the coupling 12 is corroded and the washer 15 is corroded. At this time, the rack shaft 22 is similarly fixed with oil or the like with a gap on the lower surface side of the coupling. In this case, the retreat limit position is a value larger than the retreat limit set value by the amount of the generated gap, and it can be determined that a gap is generated on the lower surface side of the coupling 12.
When the retreat limit position is within the permissible range (Yes), the detection operation is terminated as a normal state in which the fixed portion is not loosened.
According to the method for detecting looseness of the vertical injection rack shaft of the present invention and the device thereof, the operator can visually check the looseness of the fixed portion of the rack shaft from the detected values of the ascending limit position and the retracting limit position of the injection sleeve. It can be judged regardless. In addition, the maintenance time can be predicted or managed from the detected value of looseness.

The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.
Further, the present invention is not limited to the combinations shown in the embodiments, and can be implemented by various combinations.

The method for detecting looseness of a vertical injection rack shaft of the present invention and its device have industrial applicability, especially in an injection device for a vertical die casting machine provided with a position detection unit for measuring a speed displacement position of a plunger. Have.

1 Injection device for vertical die casting machine 2 Injection sleeve 3 Sleeve frame 4 Injection cylinder 5 Rotating shaft 6 Toribe 7 Fixed mold 8 Cavity 10 Vertical injection rack Shaft loosening detection device 12 Coupling 13 Nut 14 Plunger 15 Washer 20 Position detection unit 22 Rack shaft 23 Upper support part 24 Lower support part 30 Pinion 32 Pinion shaft 40 Encoder 50 Control unit

Claims (4)

The position detection unit, which is attached to the coupling of the injection device of the vertical die casting machine and detects the moving position of the rack axis that moves forward and backward with the plunger, sets the upper limit position when the injection sleeve is raised and the upper limit position when the injection sleeve is retracted. The process of detecting the backward limit position and
When the ascending limit position is compared with the predetermined ascending limit set value and the retreating limit position is out of the allowable range of the ascending limit set value or the retreating limit set value. The process of determining that the rack shaft attached to the coupling is loose, and
A method for detecting looseness of a vertical injection rack shaft, which comprises. The method for detecting looseness of a vertical injection rack shaft according to claim 1.
A vertical injection rack shaft characterized in that the ascending limit position and the retracting limit position detected by initially setting the rack shaft to the coupling are set to the ascending limit set value and the retracting limit set value. Looseness detection method. The method for detecting looseness of a vertical injection rack shaft according to claim 1 or 2.
The rack shaft is inserted into the perforation of the coupling provided in the coupling at the upper end side, and a nut is screwed into the tip to fix the rack shaft to the coupling.
When the ascending limit position is outside the permissible range of the ascending limit set value, the control unit determines that the upper surface side of the coupling is loose, and when the retreating limit position is outside the permissible range of the retreating limit set value. A method for detecting looseness of a vertical injection rack shaft, which comprises determining that the lower surface side of the coupling is loose. It has a rack shaft whose upper end side is fixed to a coupling along the advancing / retreating direction of the injection sleeve of the injection device of a vertical die casting machine, and an encoder that measures the moving distance of the rack shaft, and detects the moving position of the rack shaft. Position detection unit and
Based on the ascending limit position when the injection sleeve is raised and the value measured by the position detection unit of the retracting limit position when the injection is retracted, the ascending limit position is set to a predetermined ascending limit setting value, and Control to determine that the rack shaft attached to the coupling is loose when the retractable limit position is compared with a predetermined retractable limit set value and is out of the allowable range of the ascending limit set value or the retracted limit set value. Department and
A device for detecting looseness of a vertical injection rack shaft, which is characterized by having.

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