JPH0584448U - Mold for casting - Google Patents

Abstract

(57) [Summary] [Purpose] To make the molten metal flow velocity uniform in the vertical runner. [Structure] The flow passage cross-sectional area of the vertical runner portion 3 communicating with the sprue 2 is temporarily reduced from the upper side to the lower side so that the flow velocity of the molten metal flowing into the sprue 2 is made as uniform as possible, and the flow passage of this portion is formed. Has a flat cross-sectional shape that expands in the direction of the mold dividing surface, facilitating mold release during mold division.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mold used for gravity casting.

[0002]

[Prior Art]

 In the so-called gravity casting method in which the molten metal is poured by its weight, the molten metal poured into the sprue is guided from the vertical runner to the horizontal runner, and further from the gate to the cavity, while the temperature of the molten metal is gradually increased. It is necessary to control so that the temperature of the primary crystal will be almost the same at the stage of entering the cavity after finally lowering the temperature.

For this reason, the vertical runner portion of the die has a role of guiding the molten metal in a turbulent state at high temperature to the horizontal runner portion at a high speed, and the shape of the vertical runner portion depends on the molding. From the point of view, it has a cylindrical shape with the same cross-sectional area over the entire length, and because the flow of molten metal is faster toward the upper part, the upper part of the vertical runner part is prone to melting damage, and due to the large flow velocity immediately after the start of molten metal injection, In addition to the problem of entraining air and gas, the vertical runner section has a cylindrical shape that is deeply carved from the mating surface, so there is strong sticking to the mold during demolding. , Making the release work difficult.

[0004]

[Problems to be solved by the device]

 The present invention has been made in view of such a problem, and an object thereof is to suppress the speed of the molten metal flow at the upper portion of the vertical runner portion to enable the melting loss and the inclusion of air and the like. It is to provide a new die for casting that can suppress the release resistance of the runner part as much as possible while suppressing it as much as possible.

[0005]

[Means for Solving the Problems]

 That is, the present invention, as a die for gravity casting to achieve such a subject, reduces the vertical runner portion on the die communicating with the pouring port as the cross-sectional area of the flow passage decreases from the upper side to the lower side. In this way, the flow path cross section is formed in a flat shape that is long in the direction of the mold dividing surface.

[0006]

【Example】

 Therefore, the embodiment illustrated below will be described. FIG. 1 shows an embodiment of the present invention.

In the figure, reference numeral 1 is a mold for gravity casting, in the center of which a vertical runner portion 2 to be described later is formed so that its upper portion communicates with the sprue 3, and further from the lower end of this vertical runner portion 2. Horizontal runners 5 and 5 extend to the left and right through ceramic filters 4 and 4 that evenly regulate the flow of molten metal. From there, the molten metal is introduced into cavity dies 7 and 7 through gates 6 and 6. Is configured.

By the way, the above-described vertical runner portion 2 has a larger flow rate cross-sectional area than the horizontal runner portion 5, and further, as shown in FIG. 2, the major axis extends along the mold dividing surface 8. It has an elliptical cross section, and by making the engraving from the mold dividing surface 8 as shallow as possible, the sticking to the molds 1 and 1 can be made small and mold release at the time of mold release becomes easy. The flow passage cross-sectional area of the vertical runner portion 2 is formed so as to decrease quadratically from the upper side to the lower side, and the flow velocity of the molten metal poured from the sprue 3 is suppressed to the upper side to increase the vertical direction. The flow velocity is made as uniform as possible over the entire length of the runner portion 2.

Therefore, when the molten metal is injected from the sprue 3 of the die 1 configured as described above into the vertical runner portion 2, the molten metal flowing in at high speed in a turbulent state forms a relatively large flow passage cross section. The velocity is greatly suppressed in the upper part, and the flow velocity flows down to the lower end of the vertical runner part 2 while equalizing the flow velocity as much as possible. It is flowed into the cavity 7 after being blown. Moreover, since the molten metal injected in this way solidifies in the vertical runner portion 2 in a flat state in the direction of the dividing surface 8, the sticking to the mold 1 is weak and the mold release after mold separation is extremely easy. Done.

Although the flow passage cross-sectional shape of the vertical runner portion 2 is elliptical in the above description, it is not limited to an elliptical shape as long as it is a flat shape that spreads in the direction of the dividing surface 8. For example, when the flat channel cross section having a hexagonal cross section having the apex on the dividing surface 8 as shown in FIG. 3, the mold release can be further facilitated.

In addition to the quadratic function, that is, the parabolic cross-sectional area temporary reducing means, the flow path of the vertical runner portion 2 can also be configured as a long taper flow path whose normal line is a straight line. If such a means for temporarily reducing the flow passage cross-sectional area is taken, the vertical runner portion 3 can be formed relatively easily.

[0012]

[Effect of the device]

 As described above, according to the present invention, the vertical runner portion of the mold used for gravity casting is formed in a long funnel shape such that the cross-sectional area of the flow passage is gradually reduced from the upper side to the lower side. The velocity of the molten metal that flows into the vertical runner portion while having a flow shape is reduced in the upper part where the flow passage cross-section area is large, so that adverse effects such as melting loss on the die and entrainment of ambient air can be eliminated. Moreover, since the flow path of this vertical runner has a flat cross section that is long in the direction of the mold dividing surface, even though the cross section of the flow path is large, it can be attached to the mold at the time of mold release. The mold release can be facilitated by reducing the amount.

[Brief description of drawings]

FIG. 1 is a plan view of a mold showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a flow path cross-sectional shape of a vertical runner portion of the same mold.

FIG. 3 is a diagram showing another example of the flow channel cross-sectional shape.

[Explanation of symbols]

 1 Mold 2 Vertical runner part 3 Sprue 5 Horizontal runner part 7 Cavity 8 Mold dividing surface

Claims (1)

[Scope of utility model registration request] 1. A mold used for gravity casting, comprising:
The vertical runner part on the mold that communicates with the pouring port is designed so that the cross-sectional area of the flow path decreases gradually from the top to the bottom, and the cross-sectional shape of the flow path is a flat shape that is long in the mold dividing surface direction. A mold for casting characterized by being formed.