JPS6277168A - Centrifugal casting device - Google Patents

Abstract

PURPOSE:To repeatedly make efficient casting operations by providing a mechanism to quickly stop a rotating arm upon ending of casting then to automatically return the arm to a normal position. CONSTITUTION:A piston 61 of a stopper 6 is extended and a driving wheel 11 is rotated by a driving source 3 when the rotating arm 2 is not in a normal horizontal position. The driving power of said wheel is transmitted to a driving shaft 1 by a coil spring 12 to cooperatively rotate the shaft. A clutch member 5 rotates as well to contact with a clutch pin 4, thus cooperatively rotating the arm 2. A stopper rod 25 contacts with a piston 61 to stop the rotation of the arm 2. The position of the arm is detected and stored by the 1st sensor 13. The wheel 11 is further rotated to charge up the spring 12 and the position thereof is detected and stored by the 2nd sensor 14. The piston 61 is retreated to release the accumulated elastic force of the spring 12 and the arm 2 is quickly rotated, by which centrifugal casting is executed. The member 5 throws the pin 4 into a hole 24 to continue the rotation when the arm 2 rotates. A governor plate 42 quickly slows down the rotation of the arms 2 by the contact resistance with the member 5 and the pin 4 when the casting ends.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an apparatus for performing centrifugal casting of metal materials, glass materials, etc. Improvement of a centrifugal casting device which is a suitable device and which biases (charges up) a coil spring in the winding direction and injects molten material for casting into a mold by using the centrifugal force of rotation of a rotating arm due to the accumulated elasticity of the coil spring. Regarding.

(Prior Art) Conventionally, centrifugal casting apparatuses have often been employed for casting dental prosthesis and restorative components using metal or glass materials. An example of such a centrifugal casting device is 1.
A casting crucible and a mold are closely held at one end of the rotating arm, and the rotating arm is instantaneously rotated at high speed by the accumulated elasticity of the coil spring charged up in the winding direction, and the crucible is rotated by the centrifugal force. A device was used in which the molten material for casting was injected into the mold for casting.

(Problem to be Solved by the Invention) However, in the above device, the coil spring is charged up by manually rotating the rotary arm, and the charged up state is maintained by a locking pin that is manually inserted and removed. Therefore, preparatory work before casting was time consuming and dangerous. In addition, since the rotating arm rotates freely even after casting, it takes time to attach and detach the next mold or fill the crucible with melted material for casting, and the rotating arm stops at an arbitrary position. Therefore, each time, it was necessary to manually return it to its normal position before moving on to the next process, which was a hassle. Furthermore, since the coil spring gets fatigued over time, if you manually charge it up as described above, it will reach zero level (horizontal position of the rotating arm).
There was also the problem that it was extremely difficult to keep the amount of charge up (which greatly affects the rotational speed of the rotary arm) constant at all times. These operational difficulties are a major bottleneck in automating such devices, and drastic improvements have been strongly desired.

(Object of the Invention) The present invention has been made in view of the above, and the rotating arm of the above-mentioned device stops as soon as possible at the end of casting, and after stopping, it automatically returns to the normal position [l yen]. The purpose of the present invention is to provide a novel centrifugal casting apparatus that is capable of automatically performing a series of operations without being placed on standby for the casting process.

(Means and Embodiments for Solving the Problems) The structure of the present invention for achieving the above object will be explained based on the attached embodiment diagrams. Fig. 1 is a perspective view showing an example of the centrifugal casting device of the present invention, Fig. 2 is a partially cutaway plan view of the main parts of the same device, Fig. 3 is a perspective view of the area marked with ■ in Fig. 2, and Fig. 4 is FIG. 3 is an enlarged sectional view taken along the line IV-IV, and FIGS. 5(a) and 5(b) are explanatory diagrams showing the operating state of the clutch pin employed in the present invention. That is, the device of the present invention comprises a drive shaft 1, a rotating shaft supported at the tip of the drive shaft 1 so as to be relatively rotatable, and capable of holding a casting crucible 21 at one end and a mold 22 closely to each other on its distal side. an arm 2; a coil spring 12 which is fitted onto the drive shaft 1 and is connected to a drive wheel 11 having one end mounted on the drive shaft 1 and the other end rotatable relative to the drive shaft 1;
a drive source 3 that is connected to the drive wheel 11 and charges and amplifies the coil spring 12 in the winding direction;

a clutch pin 4 elastically mounted on the rotating arm 2 so as to be retractable in parallel with the drive shaft 1 by a compression spring 41;
It is fixed to the drive shaft 1 at a position close to the rotary arm 2, and in the direction of rotation of the drive shaft 1, comes into contact with the peripheral body of the clutch pin 4, causing the drive shaft 1 and the rotary arm 2 to rotate together, and vice versa. In the direction, there is a clutch member 5 in which the clutch pin 4 is recessed so that it slides on the top of the clutch pin 4, a stopper 6 for stopping the rotating arm 2 in a fixed position, and a rotation of the drive shaft 1. A centrifugal casting apparatus comprising a first sensor 13 for detecting the position and setting the zero level of the rotary arm 2, and a second sensor 14 for detecting the rotational position of the drive wheel 11. be.

In the figure, reference numeral 23 denotes a balance weight for balancing the crucible 21, mold 22, etc., and is attached so as to be adjustable along the axial direction of the rotary arm 2. The crucible 21 and the mold 22 communicate with each other through pores and cavities (both not shown) formed in each, and the molten casting material melted in the crucible 21 is transferred into the mold 22 by centrifugal force. It is designed to migrate. Reference numeral 7 denotes an electric furnace for melting the casting material, and when the rotary arm 2 is in the casting preparation position (horizontal position), it is tilted and the melted casting material is poured into the crucible 21. 8 is a casing that covers the above-mentioned apparatus and the electric furnace 7, etc., and 81 is a safety cover hinged to the side of the casing, which covers the rotating parts during casting. Further, reference numeral 9 denotes an operation panel containing control equipment for the apparatus, and by operating various operation buttons on the surface of the operation panel 9, a series of casting processes to be described later are executed.

Two pawl pieces 51,51 are provided on the clutch member 5 and extend in the centrifugal direction symmetrically with respect to the rotation center thereof. Each claw piece 51
One side is a flat surface 511 so that it can rotate together with the rotating arm 2 when it comes into contact with the clutch pin 4, and the opposite side is a slope 512.
When the clutch pin 4 comes into contact with the clutch pin 4, the clutch pin 4 is retracted and slides on the top of the clutch pin 4, so that the arm 2 is not restricted by the clutch member 5 and can rotate relative to the clutch pin 4.

The clutch pin 4 is made of a cylindrical member, and is elastically loaded into a hole 24 formed at the base of the rotary arm 2 by a compression spring 41 so as to be freely retractable. Its top is semi-spherical so that when the slope 512 comes into contact with it, it slides smoothly.

In the figure, reference numeral 431 denotes a buffer material made of felt, rubber, etc., for alleviating the WI hitting noise between the rotary arm 2 and the E-ring 43 when the clutch pin 4 reciprocates within the hole 24.

A shaft 42 is attached to the base of the rotating arm 2 near the clutch pin 4.
1, the governor plate 42 is rotatably attached to the shaft, and when the rotating arm 2 rotates at high speed for casting, the centrifugal force causes the governor plate 42 to swing along the base of the rotating arm 2 in the centrifugal direction using the shaft 421 as a fulcrum. It is made to be. Rotating arm 2
is released from the restriction of the stopper 6 and begins to rotate at high speed, and the clutch pin 4 is recessed into the hole 24 by the action of the slope 512. At this time, the governor plate 42 is moved by the centrifugal force as described above and protrudes again. It functions to lock onto the top of the clutch pin 4 to prevent its protrusion.

A coil spring 12 is fitted around the drive shaft 1. One end of the spring 12 is hooked to a slit 121 separately provided at the base end of the drive shaft 1, and the other end is fitted to the drive wheel 11. It is attached. The coil spring 12 is engaged with the slit 121 so that it can slide in the axial direction of the drive shaft 1 but cannot rotate in the circumferential direction. Further, a sensor plate 13' having a large number of through holes 131 formed in the circumferential direction is fixed to the base end of the drive shaft 1, and is combined with the first sensor 13 to detect the rotational position of the drive shaft 1. It is designed to detect. Further, on the side surface of the drive wheel 11, there are many through holes 141 in the circumferential direction.
A sensor ring 14' having a perforation therein is coaxially fixed to the drive wheel 11, and in combination with the sensor 14, the rotational position of the drive wheel 11, that is, the degree of charge-up of the coil spring 12 is detected. being done.

The drive wheel 11 is shown as a wheel gear in the illustrated example, and is connected to an electric motor 3 with a brake as a drive source via a pinion gear 31, and the driving force of the motor 3 causes the rotary arm 2 to be placed in a normal horizontal position. , or the coil spring 12 is charged up in the winding direction. Note that the connection relationship between the drive wheel 11 and the drive source 3 is not limited to this embodiment, and a transmission means such as a timing belt or a chain may also be used.

Further, in this embodiment, a bush-pull plunger 6 disposed parallel to the drive shaft 1 is used as the stopper 6, and the plunger 6 is controlled by an external signal (controlled by a control device in the operation panel 9). (0N-OFF signal)
This causes the electromagnetic actuation mechanism to operate, thereby causing the rod-shaped piston 61 to expand and contract in parallel to the drive shaft 1, and when expanded, extends into the rotation locus of the rotary arm 2 and functions to prevent its rotation. A stopper 25 is fixedly installed at a position corresponding to the piston 61 of the rotary arm 2, and the stopper 25 substantially hits the extended piston 61 to prevent rotation of the rotary arm. It is maintained in the normal horizontal position in the tongue preparation stage.

(operation) The operation procedure of the apparatus having the above configuration will be explained.

■ Preparation stage before casting; rotating arm 2 is in the normal horizontal position (
If the TJ production crucible 21 is not in a position where the electric furnace 7 can be tilted to inject the molten casting material, the bush pull plunger 6 is extended and the electric motor 3 is activated, and the wheel gear 11 Rotate in the direction of arrow X.

At this time, the power is transferred to the drive shaft 1 by the coil spring 12.
, the drive shaft 1 is rotated in the same direction, and the clutch member 5 is also rotated to rotate the flat surface 51 of the claw piece 51.
1 hits the clutch pin 4, causing the rotary arm 2 to also rotate in cooperation with the clutch pin 4. The rotary arm 2 rotates around the axis of the drive shaft 1, and the stop bar 25 is connected to the bush pull plunger 6.
The rotation of the rotating arm 2 stops when the piston 61 hits the piston 61 .

At this point, the first sensor 13 detects its position and recognizes the zero level.

In this state, the rotation of the rotary arm 2 in the above-mentioned X direction is completely prevented, but since it is unstable in the opposite direction, it is inconvenient when the mold 22 etc. are installed next. 3 further drives wheel gear 11 to
When the drive shaft 1 is rotated in the direction, the drive shaft 1 cannot rotate due to the action of the clutch member 5 and the clutch pin 4.
The coil spring 12 is slightly charged up in the winding direction, and the accumulated elasticity stabilizes the rotating arm 2 in both forward and reverse directions. This state is detected by the second sensor 14.
detects and stores the position, and then drives the electric motor 3 to rotate the wheel gear 11 and coil spring 1.
Charge up 2.

Here, the detection position by the sensor 14 and the above sensor 1
The difference from the zero level detected by step 3 becomes the charge-up amount corresponding to the rotational force during casting, and is appropriately windowed depending on the characteristics or amount of the material to be cast. coil spring 1
2 becomes fatigued over time, so if this charge-up is simply performed mechanically, the amount of charge-up will change and the rotational force of the rotating arm 2 will vary accordingly. However, in the present invention, the first sensor 13 Since the level is detected and the charge-up amount is detected by the second sensor 14, if a predetermined charge-up amount is programmed in advance, the electric motor 3 will operate accordingly, and the charge-up amount will always be constant, that is, the rotation A predetermined rotational force of the arm 2 can be obtained.

(■ Injection of monthly charge for casting and installation of mold; Crucible for casting 2
1 and the mold 22 are respectively set at predetermined positions on the rotating arm 2, and the casting material melted in advance in the electric furnace 7 is placed in the electric furnace 7.
The liquid is injected into the crucible 21 by tilting the . The preparation for casting is now complete, so move on to the next step immediately.

■ Casting: In the above state, the accumulated elasticity of the charged-up coil spring 12 is against the rotating arm 2 whose rotation is prevented by the bush pull plunger 6.
Since the force is concentrated on the clutch pin 4 in the X direction, when the piston 61 of the plunger 6 is retracted, this restriction is released and the rotary arm 2 starts rapidly rotating in the X direction, instantly The melted material for casting in the crucible 21 reaches approximately 11,000 rpm, and due to the centrifugal force, the melted material for casting is heated to the mold 22.
is injected and casting is performed. At this time, the clutch member 5
is stationary, and as the rotating arm 2 rotates, the clutch pin 4 comes into contact with a surface 512 of the clutch member 5 opposite to the contact surface (i.e., flat surface 511) [see FIG. 5(a)]. However, since the surface 512 is a slope, the clutch pin 4 resists the elasticity of the compression spring 41 and sinks into the hole 24 due to the component force at the time of contact, and as a result, the rotating arm 2
continues to rotate. The governor plate 42 attached near the clutch pin 4 is prevented from swinging in the centrifugal direction due to centrifugal force, and when the clutch pin 4 is retracted as described above, the governor plate 42 engages with the top of the clutch pin 4. to prevent its protrusion [see Figure 5 (b)]. Therefore, the clutch member 5 continues to rotate without hitting the clutch pin 4 (actually, the clutch pin 4 rotates) 6 Thus, the casting is completed in 10 to 20 seconds, and at the same time the rotation speed of the rotating arm 2 is changed to another. When the centrifugal force on the governor plate 42 decreases due to the resistance of the constituent members, the governor plate 42 returns to its original position at some point. As a result, the clutch pin 42 is released from the clutch pin 4, and as a result, the clutch pin 42 protrudes again due to the restoring elasticity of the compression spring 41, and rotates while intermittently hitting the clutch member 5. The function of the governor plate 42 is to minimize the resistance to the rotating arm 2 during casting to maintain a proper rotational speed and eliminate unpleasant contact noise, and also to prevent the clutch pin 4 and the clutch member 5 from forming when casting is complete.
This is preferably adopted because it functions to reduce the rotational speed of the rotary arm 2 as quickly as possible due to the contact resistance with the rotary arm 2. However, it goes without saying that the present invention is not limited to the illustrated example, and other modifications are possible.

In this way, a series of casting operations are completed, and the rotating arm 2
Since the casting machine stops at an arbitrary position, if the next casting operation is to be continued, the operation can be started from step (1) above, and the same casting operation can be repeatedly performed efficiently.

The above series of operations is performed on the operation panel 9 as a - cycle.
Programming can be done using the built-in control equipment, and automatic operation can be performed by pressing a button. It goes without saying that it is also possible to install the rotary arm 2 in a normal horizontal position and program this stage as the starting position.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that other changes may be made to the first and second sensors 13, 14, the stopper 6, the driving source 3, etc. do not have.

(Effects of the Invention) As described above, in the device of the present invention, the rotating arm can be automatically and quickly installed at the proper position for preparing for casting, and after casting is completed, the rotating arm can be rotated by the action of the clutch pin and the clutch member. Since the rotational speed of the arm is rapidly reduced, the interval between operations is shortened, and even when a large number of casting operations are to be performed, they can be carried out extremely efficiently. Furthermore, since the drive shaft and drive wheel are each equipped with a sensor to detect the rotational position, even if the coil spring becomes fatigued over time, the combination of the sensor signals from both will ensure that the rotary arm reaches the zero level. It is always set correctly and a predetermined charge-up amount of the coil spring can be obtained with good reproducibility. Furthermore, it is possible to automatically control a series of operations of the device of the present invention, including the temperature control of the electric furnace for melting casting materials and its tilting mechanism, and all operations can be performed with the touch of a button, except for the installation of the mold. Operations will be automated.

The present invention, which has many advantages worthy of special mention as described above, is extremely useful.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of the centrifugal casting apparatus of the present invention;
The figure is a partially cutaway plan view of the main part of the device, Figure 3 is a perspective view of the part marked with ■ in Figure 2, Figure 4 is an enlarged sectional view taken along the line IV-IV in Figure 3, and Figure 5 (A). (b) is an explanatory diagram showing the operating state of the clutch pin adopted in the present invention. (Explanation of symbols) 1... Drive shaft, 11... Drive wheel (
wheel gear), 12... coil spring,
13...first sensor, 14...second
12... Rotating arm, 21... Casting crucible, 22... Mold, 3... Drive source (electric motor), 31... Pinion gear, 4...
・Clutch pin, 41...compression spring,
42... Governor plate, 5... Clutch member,
6... Stopper (button pull plunger)
. one or more one

Claims (1)

[Claims] 1. A centrifugal system in which a coil spring is biased in the direction of the winding, a rotary arm is rotated by the accumulated elasticity, and a molten material for casting is injected into a mold by the rotational centrifugal force of the rotary arm to perform casting. In a casting device, there are a drive shaft and a rotary arm supported at the tip of the drive shaft so as to be relatively rotatable, and capable of holding a casting crucible at one end and a mold closely to each other on its distal side. ¥, coil springs ¥ and ¥, each of which is connected to the drive wheel, which is fitted onto the drive shaft and whose one end is attached to the drive shaft and the other end is connected to the drive wheel so as to be rotatable relative to the drive shaft. drive sources for biasing the coil spring in the winding direction; clutch pins and clutch pins mounted on the rotary arm so as to be retractable in parallel with the drive shaft by means of a compression spring; and a clutch pin located close to the rotary arm. is fixed to the drive shaft, and in the direction of rotation of the drive shaft, contacts the peripheral body of the clutch pin to cause the drive shaft and rotating arm to rotate together, while in the opposite direction, the clutch pin is retracted and the clutch pin is fixed to the drive shaft. A clutch member that slides on the top of the rotary arm, a stopper that stops the rotary arm at a fixed position, and a stopper that detects the rotational position of the drive shaft and sets the zero level of the rotary arm. 1st of
A centrifugal casting apparatus characterized in that the centrifugal casting apparatus comprises sensors ¥ and ¥, and second sensors ¥ and ¥ that detect the rotational position of the drive wheel. 2. A governor plate that is slidable along the rotating arm is attached near the clutch pin, and when the rotating arm rotates and centrifugal casting is performed, the governor plate moves toward the centrifugal side due to the centrifugal force of the rotation, and closes the clutch pin. Claim 1 wherein the clutch pin is retained in a retracted state by being engaged with the pin.
Apparatus described in section.