JPS6254572B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vertically facing frameless sand mold for casting that is molded by a high-speed molding machine and is pushed by the extrusion force of the molding machine and advances in a line on a pouring table. This relates to a device that prevents deformation during pouring.

In the case of frameless casting sand molds made with high-speed molding machines, such as desamate molding machines, and with a vertical cutting method in which the molds are pushed by the extrusion force of the molding machine and are connected in a line and move intermittently over the pouring table, the sand molds are molded using a high-speed molding machine. Alternatively, after pouring, the dimensions of the cast product tend to vary greatly due to cracks on the sides of the sand mold or expansion of the casting wall of the pouring cavity.

To prevent this, measures should be taken such as increasing the contact area of the sand mold dividing surface and reducing the number of products attached to increase the strength, or increasing the counter pressure of the sand to increase the strength of the sand mold. Although this can be solved to some extent, it is not sufficient; in the former case, the number of products per sand mold decreases, resulting in a decrease in productivity, and in the latter case, the amount of bentonite added As a result of increasing the amount of water, the moisture content increases, which tends to cause sand shelving in the sand tank or blowhole, reducing production or increasing costs.

Another possibility is the so-called dressing frame method, in which the sides of the sand mold are sloped and a casting flask called a dressing frame is later fitted to prevent the casting wall from spreading during pouring. Since it has to be held on the frame, the weight of the dressing frame becomes large, and this is loaded onto the sand mold, requiring the extrusion force of the molding machine to be increased, resulting in a force that exceeds the strength of the sand mold. This acts on the sand mold dividing surface and destroys the sand mold, or the indentation becomes larger than the expected value in the model design, making it difficult to obtain a cast product with good dimensional accuracy.

The present invention solves the above-mentioned problems of vertically facing frameless sand molds that are continuously pushed forward in rows on a pouring table, thereby preventing defects in cast products and reducing fluctuations in dimensional accuracy. The aim is to provide a device that can be made smaller and improve production efficiency.It is a vertical milling machine that is continuously molded at high speed and moves intermittently in a line on the pouring table using the extrusion force of the molding machine. It has a gripping device that presses both sides of the row of sand molds with a presser plate in the middle of the row of frame sand molds, at least in a portion including the pouring position, and a suspension device that puts the weight of the gripping device in a state where no load is placed on the sand molds. This invention relates to a clamping device for casting sand molds that is equipped with a trolley that travels on the ground.

By the way, in order to suppress the expansion of the frameless sand mold during pouring and to stabilize the dimensions of the cast product, the sand mold is basically heated at least in the area that includes the pouring position, preferably until the so-called tension of the cast product disappears. It is necessary to continue clamping with a rigid holding plate. The most suitable device for this purpose in a continuous molding and pouring work line is that the holding plate that clamps the sand mold clamps the sides of the sand mold, and the weight of these gripping devices is not applied to the sand mold, so the sand mold The gripping device moves with the sand mold without increasing the extrusion force of the molding machine that acts on it, and the clamp is released at the desired location at the desired time after pouring, and the entire clamping device returns to its original position. It is desirable that the device is capable of The clamp device of the present invention is a device that meets these conditions.

Next, embodiments shown in the accompanying drawings will be described.

Frameless sand molds 1 formed by a high-speed molding machine (not shown) are successively extruded onto skid rails 2 of a pouring table 3, and are moved forward in a line in close contact with each other by the extrusion force of the molding machine. Holding plate 4 that holds down both sides of the sand mold
are each attached to the tip of a piston rod 6 of a cylinder 5 operated by fluid pressure. Presser plate 4
It is desirable that the sand mold is made of a rigid body such as cast iron that does not deflect when the sand mold is clamped, and that the pressing surface is machined flat.

Further, it is desirable that the presser plate 4 is located approximately at the center in the height direction of the sand mold, and has a height that is in contact with 60% or more, preferably 80% or more of the height of the sand mold. Further, it is effective that the width of one presser plate 4 is such that it can come into contact with the side surfaces of three to five sand molds.

The fluid pressure cylinder 5 is assembled into a mounting bracket 7, and the flanges 8 at both ends of the mounting bracket 7 are attached to upper and lower H-beams 1 of the framework of the gripping device, which will be described later, via vibration isolating rubber 9.
The holding plate 4 is attached to a mounting plate 17 provided between the sand mold and the sand mold, and as the piston rod 6 moves back and forth, the presser plate 4 is pressed against the side surface of the sand mold to clamp the sand mold or release the clamp. Therefore, the presser plate 4
Due to the flexibility of the anti-vibration rubber 9, the vibration isolating rubber 9 comes into contact with the side surface of the sand mold, and clamps the sand mold from the side with an even pressure. Guide holes 16 are provided near both ends of the mounting bracket 7, and guide rods 11 provided on the presser plate 4 are inserted through the guide holes 16 to support the presser plate.
A compressed spring 12 is inserted through the guide rod 11 between the mounting bracket 7 and the holding plate 4, and the piston 6 is inserted so as to move the piston rod 6 of the cylinder 5 forward.
Even after the fluid pressure acting on a is released, the elasticity of the spring 12 allows the presser plate 4 to press lightly against the side of the sand mold, which is convenient for removing sand from the presser surface of the presser plate 4, as described later. It is.

The upper and lower H-beams 10 to which the mounting brackets 7 are attached must have high rigidity and must not cause deflection, and the gate frame 12 is attached to the H-beams 10 on both sides of the sand mold. It constitutes the framework of a gripping device that is part of the clamping device. The gate frame 12 is suspended from a traveling trolley 14 via a balancer or suspension device 13.
The left and right running trolleys 14 are connected by a beam 15,
Together they form the framework of the clamping device.
The framework and parts of the clamping device are sufficiently protected against flying sand during molding, falling sand from the moving sand mold, flying molten metal during pouring, radiant heat of the molten metal, and steam and corrosive gas generated from the poured sand mold. Must be shielded or isolated.

For traveling, the trolley itself mounted on an I-beam may be self-propelled by an electric motor or the like, or it may be moved simultaneously when the sand mold is extruded by the extrusion force of the molding machine.

The most important point is how to run the gripping device while clamping the sand mold without imposing the weight of the gripping device on the sand mold on the skid of the pouring table. In the present invention, a balancer 13 is provided between the running part of the ceiling and the gate frame at both ends of the sand mold gripping device below, so that the weight of the gripping device is balanced and suspended by the balancer, and the weight of the gripping device is placed on the sand mold. It is designed so that it does not get affected. For example, as a balancer,
A type that has a built-in spring and suspends the gate frame via the spring can be used.

Therefore, for example, even if the traveling trolley does not run on its own, the entire clamping device can move smoothly while clamping the sand mold in synchronization with molding, using only the extrusion force of the molding machine. The clamp device is returned by releasing the clamp and then driving the trolley in reverse rotation, or by hand.

The length of the gripping device, the length of the H-shaped steel with the push plate attached, or the distance between the two gate formworks is sufficient to keep clamping the sides of the sand mold from pouring until the so-called tension in the casting disappears. It is effective to set the length or interval to a suitable length or interval.

Since the structure is as described above, this clamping device is installed in the pouring station, and the cylinder 5 is operated to hold down the plurality of sand molds 1 that are pushed by the molding machine and move forward in a connected manner on the skid. Board 4
Clamp by pressing from both sides. Since the cylinder 5 is attached to the frame via a flexible vibration isolating rubber 9, the holding plate 4 can follow the side surface of the sand mold and clamp the side surface of the sand mold with a uniform force. In this manner, the sand mold 1 is successively poured with the pouring station. Once the last sand mold in the clamp device has been poured, it is moved forward until the tension disappears, and then the clamp is released. Since the presser plate 4 is lightly in contact with the side surface of the sand mold due to the force of the spring 12, the sand attached to the presser plate surface can be removed by sliding the presser plate 4 along the side surface of the sand mold and returning the clamp device to its original position. It is rubbed off by friction. Thereupon, the rows of sand molds are again clamped by the gripping device, and the above operations are repeated by sequentially pouring the metal.

As described above, since the clamping device of the present invention is designed to clamp both sides of the sand mold of continuous molding using an automatic molding machine, which was conventionally cast without a frame, the tension of the sand mold during pouring can cause damage to the sand mold. Accidents such as damage or cavity expansion can be prevented, the number of pieces to be bonded can be increased, and cast products with good dimensional accuracy can be obtained, yields can be improved, and
It becomes possible to reduce machining fees, molding sand costs, etc., which has a great practical effect.

[Brief explanation of the drawing]

Fig. 1 is a front view of an embodiment of the present invention, Fig. 2 is a side view showing one side of the clamp device, Fig. 3 is a sectional view showing the mounting state of the holding plate and the fluid pressure cylinder, and Fig. 4 is the same. It is a front view. 1...Sand mold, 2...Pouring table skid, 3...Pouring charge, 4...Holding plate, 5...Fluid pressure cylinder, 6
...Piston rod, 6a...Piston, 7...
Mounting hardware, 8...Flange, 9...Vibration isolation rubber, 1
0... H-shaped steel, 11... Guide rod, 12... Spring, 13... Balancer, 14... Running trolley, 15... Beam, 16... Guide hole.

Claims (1)

[Claims] 1. A row of vertically-opened frameless sand molds that are continuously molded at high speed and are intermittently advanced in a line on a pouring table by the extrusion force of the molding machine, including the pouring position. A clamping device for a sand mold for casting, comprising a gripping device that presses both sides of the sand mold with presser plates, and a trolley that travels with a suspension device that puts the weight of the gripping device in a state where no load is placed on the sand mold.