Molding machine

Abstract

To provide a molding machine capable of preventing the rotation of the plunger rod. [Solution] This molding machine 100 includes a molding machine body 101 to which a mold M is fixed, and a plunger 3 including an injection sleeve 2 provided on the molding machine body 101, a plunger tip 30 that fits into an injection through hole 20 of the injection sleeve 2, and a plunger rod 31. The plunger tip 30 and the injection through hole 20 are formed in a non-circular shape that fits together when viewed from the direction of movement of the plunger 3.

Description

Technical Field

[0001] The present invention relates to a molding machine, and more particularly to a molding machine provided with a plunger and an injection sleeve.

Background Art

[0002] Conventionally, a molding machine provided with a plunger and an injection sleeve is known (for example, see Patent Document 1).

[0003] The above Patent Document 1 discloses a die casting machine provided with a plunger having a plunger tip fitted into an injection sleeve, and a plunger rod to which the plunger tip is fixed. The plunger tip is provided with an internal space to which cooling water is supplied via a cooling water passage provided in the plunger rod. A cooling water hose for supplying cooling water to the cooling water passage is connected to the plunger rod.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the die casting machine disclosed in the above Patent Document 1, when the plunger tip slides inside the injection sleeve, the plunger tip receives contact resistance from the injection sleeve, and the plunger tip and the plunger rod may rotate. In this case, the cooling water hose connected to the plunger rod will also rotate, which may loosen the connection of the cooling water hose to the plunger rod or cause the cooling water hose to come off from the plunger rod, so it is desired to prevent the rotation of the plunger rod.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide a molding machine capable of preventing the rotation of the plunger rod. [Means for solving the problem]

[0007] To achieve the above objective, a molding machine in one aspect of this invention comprises a molding machine body to which a mold is fixed, an injection sleeve provided on the molding machine body and including an injection through hole, a plunger including a plunger tip that fits into the injection through hole of the injection sleeve, and a plunger rod, wherein the plunger tip and the injection through hole are formed in a non-circular shape that fits together when viewed from the direction of movement of the plunger.

[0008] In a molding machine according to one aspect of this invention, as described above, the plunger tip and the injection through-hole are formed in a non-circular shape that fits together when viewed from the direction of movement of the plunger. As a result, even if the contact resistance received from the injection sleeve acts as a rotational force that rotates the plunger tip when the plunger tip slides inside the injection sleeve, the non-circular shape of the injection through-hole that fits into the plunger tip prevents the non-circular shape of the plunger tip from rotating. Consequently, the rotation of the plunger rod can be prevented.

[0009] In the molding machine according to the first aspect described above, preferably, the plunger tip and the injection through-hole are formed in a non-circular shape that includes a straight portion and an arc portion and fits together when viewed from the direction of movement. With this configuration, the shape of the plunger tip and the injection through-hole can be made such that the shape is simply a circular shape with a straight portion when viewed from the direction of movement, thereby preventing rotation of the plunger tip. Therefore, the rotation of the plunger rod can be easily prevented.

[0010] In the molding machine according to the first aspect described above, preferably, a cooling water hose connected to the plunger rod is provided to supply cooling water to the plunger tip, the plunger tip is provided with a cooling chamber that is cooled by the cooling water, and the plunger includes an inlet channel for introducing cooling water from the cooling water hose into the cooling chamber and an outlet channel for leading the cooling water from the cooling chamber towards the plunger rod, with the outlet channel being positioned above the inlet channel. With this configuration, rotation of the plunger tip can be prevented, and a state can be maintained in which cooling water is introduced into the cooling chamber from the inlet channel on the lower side of the cooling chamber and led out from the outlet channel on the upper side of the cooling chamber. As a result, the water level in the cooling chamber can be maintained at a relatively high level, so that the plunger tip can be cooled effectively.

[0011] In the configuration in which the plunger tip and injection through-hole described above include a straight section and an arc section, preferably, the straight section extends horizontally upward when viewed from the direction of movement, and the arc section is connected from below to both ends of the straight section when viewed from the direction of movement. With this configuration, the plunger tip and injection through-hole are formed in a D shape by one straight section and one arc section, so that the rotation of the plunger tip can be prevented with a plunger tip and injection through-hole of a simple shape. Therefore, the rotation of the plunger rod can be prevented with a plunger tip and injection through-hole of a simple shape.

[0012] In this case, preferably, the arc portion has a central angle greater than 180 degrees such that the straight portion is located above the center of the arc portion. With this configuration, it is possible to avoid the central angle of the arc portion being 180 degrees or less, which would cause the non-circular plunger tip and injection through-hole to become elongated in the width direction. As a result, it is possible to suppress the unstable movement of the non-circular plunger tip sliding within the injection sleeve.

[0013] In a configuration where the straight section is located above the center of the arc section, preferably, in a direction perpendicular to the direction of movement, the central axis of the plunger rod is positioned on the opposite side of the arc section from the side where the straight section is located. This configuration prevents the plunger rod from being positioned off-center towards the straight section, which is the edge of the plunger tip. As a result, it is possible to further suppress instability in the movement of the non-circular shaped plunger tip sliding within the injection sleeve.

[0014] In the molding machine according to the first aspect described above, preferably, the plunger tip includes a convex portion that protrudes from the front surface of the plunger in the forward direction of the plunger, the convex portion has a flat upper surface, and is equipped with a molten metal detection unit that detects the relative position of the molten metal poured into the injection sleeve with respect to the upper surface. Here, in a molding machine, the oil surface inside the injection sleeve may become wavy in the initial stages of pouring, and this wavy surface gradually subsides as the oil surface rises. Therefore, with the above configuration, the amount of molten metal poured can be obtained using the upper surface as a reference by the molten metal detection unit, so it is possible to detect the molten metal after the oil surface has risen, rather than the molten metal in the initial stages of pouring when the oil surface is wavy. Thus, it is possible to suppress the decrease in accuracy when obtaining the amount of molten metal due to the wavy surface of the oil surface during pouring. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a molding machine that can prevent the rotation of the plunger rod, as described above. [Brief explanation of the drawing]

[0016] [Figure 1] This diagram shows the overall configuration of a molding machine according to an embodiment. [Figure 2] This is a cross-sectional view showing the injection sleeve, plunger, and molten metal detection unit of a molding machine according to an embodiment, viewed from the side. [Figure 3] This is a cross-sectional view along line III-III in Figure 2. [Figure 4]This is a graph for explaining the relationship among time, the temperature detected by the molten metal detection unit, and the ratio of the poured molten metal in the molding machine according to the embodiment. [Figure 5] This is a cross-sectional view showing the injection sleeve and plunger of a modified example, corresponding to Fig. 3 of the embodiment. [Figure 6] This is a diagram showing the overall configuration of the molding machine of the modified example. [Mode for Carrying Out the Invention]

[0017] (Embodiment) The configuration of the molding machine 100 according to the embodiment will be described with reference to Fig. 1 to Fig. 4.

[0018] In each drawing, the direction in which the plunger tip 30 moves is indicated by the X direction. The forward movement direction of the plunger tip 30 in the X direction is indicated by the X1 direction, and the backward movement direction is indicated by the X2 direction. The X direction is the horizontal direction, and is also the movement direction (mold clamping and mold opening direction) of the mold M. In short, the molding machine 100 is a so-called horizontal type apparatus in which the movable mold M2 moves in the lateral direction. Further, in each drawing, the axis located at the center of the plunger rod 31 extending in the X direction is indicated by the central axis C1.

[0019] In each drawing, the vertical direction is indicated by the Z direction. The upper side in the Z direction is indicated by the Z1 direction, and the lower side is indicated by the Z2 direction.

[0020] In each drawing, the direction orthogonal to the X direction and the Z direction is indicated by the Y direction. That is, the depth direction of the molding machine 100 is indicated by the Y direction.

[0021] (Configuration of Molding Machine) The molding machine 100 shown in Fig. 1 is a die casting machine. Specifically, the molding machine 100 is configured to mold a die-cast product by injecting molten metal into the cavity CA of the mold M constituted by the fixed mold M1 and the movable mold M2 and solidifying the molten metal in the cavity CA. As an example, the metal material used for molding is an aluminum alloy, a zinc alloy, a magnesium alloy, or the like.

[0022] The molding machine 100 comprises a molding machine body 101 to which the mold M is fixed, and an injection structure 102 for injecting molten metal into the mold M fixed to the molding machine body 101.

[0023] (Configuration of the molding machine body) The molding machine body 101 includes a fixed die plate 101a, a movable die plate 101b, a tie bar 101c, and a mold clamping device 101d.

[0024] The fixed die plate 101a is a rectangular metal plate-shaped member with the X direction as the thickness direction. The fixed die plate 101a is configured so that the fixed mold M1 is fixed to its end face on the X1 direction side by a clamp or the like. The injection sleeve 2 is provided on the fixed die plate 101a (molding machine body 101) so as to protrude from its end face on the X2 direction side.

[0025] The movable die plate 101b is a rectangular metal plate-like member with the X direction as the thickness direction. The movable die plate 101b is configured such that the movable mold M2 is fixed to its end face on the X2 direction side by a clamp or the like, so as to face the fixed mold M1 which is fixed to the fixed die plate 101a.

[0026] The tie bars 101c are a plurality of columnar members extending in the X direction, and are inserted through holes provided at the four corners of the movable die plate 101b. The tie bars 101c are configured to hold the movable die plate 101b while guiding its movement in the X direction. In other words, the tie bars 101c are guide members for clamping and opening the mold M.

[0027] For example, the clamping device 101d includes a toggle mechanism for moving the movable die plate 101b in the X direction and a drive source for driving the toggle mechanism. This drive source is either hydraulically driven or electrically driven.

[0028] (Configuration of injection structure) As shown in Figure 1, the injection structure 102 comprises an injection cylinder 1, an injection sleeve 2, a plunger 3, a cooling water hose 4 connected to a plunger rod 31, a molten metal detection unit 5, and a control unit 6.

[0029] The cooling water hose 4 includes a supply hose 4a that supplies cooling water to the plunger tip 30 and a discharge hose 4b that discharges cooling water from the plunger tip 30. The cooling water hose 4 is positioned outside the injection sleeve 2 so as not to interfere with the injection sleeve 2 at the limit of the plunger 3's forward movement.

[0030] (Configuration of the cylinder in the injection structure) The injection cylinder 1 is configured to move the plunger 3 back and forth within the injection sleeve 2. In other words, the injection cylinder 1 is the drive source for the plunger 3. This drive source is either hydraulically driven or electrically driven. The injection cylinder 1 is located on the other side (X2 direction side) of the plunger 3.

[0031] The injection cylinder 1 includes a cylinder rod 10. The cylinder rod 10 is connected to the plunger rod 31 from the other side (X2 direction side). The plunger rod 31 and the cylinder rod 10 are connected by a coupling 7 such that their central axes are approximately aligned. Note that no cooling water flows through the cylinder rod 10.

[0032] (Configuration of injection sleeve and plunger) The injection sleeve 2 is formed in a cylindrical shape that extends laterally (in the X direction). That is, the injection sleeve 2 includes an injection through hole 20 that extends laterally (in the X direction). The injection sleeve 2 also includes a pouring port 21 that opens upwards into which the molten metal is poured.

[0033] An injection opening 2a is provided at one end (X1 direction side) of the injection through hole 20 for injecting molten metal into the mold M during injection. An introduction opening 2b is provided at the other end (X2 direction side) of the injection through hole 20 for introducing the plunger 3 into the inside of the injection sleeve 2.

[0034] The injection sleeve 2 includes a detection unit installation hole 22 for installing the molten metal detection unit 5 on the inlet opening 2b side (X2 direction side) of the pouring port 21. The detection unit installation hole 22 penetrates the upper part of the injection sleeve 2. The detection unit installation hole 22 is located in the center in the width direction (Y direction) of the injection sleeve 2. The detection unit installation hole 22 is located directly above the convex portion 35 of the plunger tip 30, which will be described later, in the standby position before injection.

[0035] The standby position is the position of the plunger tip 30 when pouring is performed. If the plunger tip is retracted during pouring, the standby position becomes the limit of the plunger tip's retraction.

[0036] The plunger 3 includes a plunger tip 30, a plunger rod 31, and a connecting part 32 (joint) that connects and fixes the plunger tip 30 and the plunger rod 31 to each other.

[0037] As shown in Figure 1, the plunger tip 30 is configured to fit into the injection through-hole 20 of the injection sleeve 2. The plunger tip 30 is located at the tip (the end on the X1 direction side) of the plunger 3. The plunger tip 30 is provided with a cooling chamber R that is cooled by cooling water supplied from the cooling water hose 4.

[0038] The plunger 3 includes an inlet channel 33 for introducing cooling water from the cooling water hose 4 into the cooling chamber R, and an outlet channel 34 for leading the cooling water from the cooling chamber R to the plunger rod 31 side.

[0039] The upstream end of the inlet channel 33 is connected to the supply hose 4a. The downstream end of the inlet channel 33 is connected to the cooling chamber R. The upstream end of the outlet channel 34 is connected to the cooling chamber R. The downstream end of the outlet channel 34 is connected to the discharge hose 4b.

[0040] The outlet channel 34 is positioned above the inlet channel 33. More specifically, the outlet channel 34 is positioned directly above the inlet channel 33 and extends in the X direction parallel to the inlet channel 33. The outlet channel 34 and the inlet channel 33 span the plunger tip 30, the connection 32, and the plunger rod 31. For example, the outlet channel 34 and the inlet channel 33 are formed by circular holes having the same diameter as each other.

[0041] Here, the cooling chamber R is constantly maintained at a water level where it is filled with cooling water to a height at least above the lower end of the outlet channel 34. The cooling water that rises to a height above the lower end of the outlet channel 34 inside the cooling chamber R is discharged from the outlet channel 34. In short, the cooling water inside the cooling chamber R is discharged to the outside of the cooling chamber R by overflow.

[0042] (Regarding the shape of the injection through-hole in the plunger tip and injection sleeve) The shape of the plunger tip 30 and the injection through-hole 20 of the injection sleeve 2 will be described.

[0043] As shown in Figure 3, the plunger tip 30 and the injection through-hole 20 are formed in a non-circular shape that fits together when viewed from the direction of movement of the plunger 3 (X direction). That is, the plunger tip 30 and the injection through-hole 20 are formed in a similar shape when viewed from the direction of movement of the plunger 3. The plunger tip 30 maintains surface contact with the injection through-hole 20 around its entire circumference when viewed from the direction of movement of the plunger 3.

[0044] Thus, because the plunger tip 30 and the injection through-hole 20 have a non-circular shape that allows them to fit together, the plunger tip 30 does not rotate relative to the injection sleeve 2. Naturally, the plunger rod 31 to which the cooling water hose 4 is connected and to which the plunger tip 30 is fixed also does not rotate relative to the injection sleeve 2.

[0045] Regarding the shape of the plunger tip 30 and the injection through-hole 20, the plunger tip 30 and the injection through-hole 20 are formed in a non-circular shape that, when viewed from the direction of movement, includes straight sections 30a, 20a and arc sections 30b, 20b that fit together. The straight sections 30a, 20a extend horizontally upward when viewed from the direction of movement, and the arc sections 30b, 20b are connected from below to both ends of the straight sections 30a, 20a when viewed from the direction of movement. In short, the plunger tip 30 and the injection through-hole 20 are formed in a D shape when viewed from the direction of movement.

[0046] Furthermore, the arc sections 30b and 20b have a central angle θ greater than 180 degrees such that the straight section 30a is located above the center C2 of the arc sections 30b and 20b. The centers of the straight sections 30a and 20a are positioned directly above the center C2 of the arc sections 30b and 20b, and directly below the center of the detection unit mounting hole 22, when viewed from the direction of movement of the plunger 3.

[0047] In a direction perpendicular to the direction of movement, the central axis C1 of the plunger rod 31 is positioned on the opposite side of the arc portion 30b's center C2 from the side where the straight portion 30a is located. Specifically, the central axis C1 of the plunger rod 31 is positioned below the center C2 of the arc portion 30b. In a direction perpendicular to the X direction, the central axis C1 of the plunger rod 31 is positioned near (or at) the center of gravity of the plunger tip 30.

[0048] Furthermore, the plunger tip 30 includes a convex portion 35 that protrudes from the front surface 3a of the plunger 3 in the forward direction (X1 direction) of the plunger 3. The convex portion 35 is a part that protrudes in the forward direction (X1 direction) from the plunger tip body, which is provided with a straight portion 30a and an arc portion 30b. When viewed from the direction of movement, the convex portion 35 has a horizontally elongated rectangular shape.

[0049] The convex portion 35 has a flat upper surface 35a. The upper surface 35a is positioned above the center C2 of the arc portion 30b. When the plunger tip 30 is in the standby position before injection, the upper surface 35a is positioned directly below and opposite the molten metal detection unit 5 (detection unit installation hole 22). Therefore, when the plunger tip 30 is in the standby position before injection, in the X direction, the molten metal detection unit 5 is positioned between the tip 35b of the convex portion 35 and the base (front surface 3a) of the convex portion 35. The upper surface 35a of the convex portion 35 is positioned at least on the X2 side of the pouring port 21 so that the molten metal poured from the pouring port 21 does not directly adhere to the upper surface 35a during pouring.

[0050] (Configuration of the molten metal detection unit and control unit) As shown in Figure 2, the molten metal detection unit 5 is installed in the detection unit installation hole 22 of the injection sleeve 2, as described above. The molten metal detection unit 5 is configured so that, when installed in the detection unit installation hole 22, it does not protrude below the lower end 22a of the detection unit installation hole 22. In short, the molten metal detection unit 5 is positioned at least above the lower end 22a of the detection unit installation hole 22 so as not to interfere with the plunger tip 30.

[0051] The molten metal detection unit 5 is configured to detect the relative position of the molten metal poured into the injection sleeve 2 with respect to the upper surface 35a of the convex portion 35 when the plunger tip 30 is in the standby position before injection.

[0052] As an example, the molten metal detection unit 5 is a non-contact temperature sensor that does not come into contact with the molten metal. Specifically, the molten metal detection unit 5 is composed of a radiation thermometer. A radiation thermometer is a thermometer that measures the temperature of an object non-contact by measuring electromagnetic waves such as infrared rays caused by the thermal energy of the object. The measurement range A of the molten metal detection unit 5 is set to the range between the molten metal detection unit 5 and the upper surface 35a of the convex portion 35.

[0053] The control unit 6 (see Figure 1) is composed of a computer including a processor such as a CPU (Central Processing Unit) and memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0054] The control unit 6 is configured to control the drive of the clamping device 101d, the pouring device (not shown), and the injection cylinder 1, etc. The control unit 6 is configured to acquire the detection signal S (see Figure 1) from the molten metal detection unit 5. The control unit 6 is then configured to perform predetermined control based on the detection signal S from the molten metal detection unit 5.

[0055] For example, the control unit 6 is configured to initiate the forward movement of the plunger 3 by the injection cylinder 1 in order to inject molten metal into the mold M, based on the detection signal S from the molten metal detection unit 5. Specifically, the control unit 6 is configured to initiate the forward movement of the plunger 3 by the injection cylinder 1 when the detected temperature exceeds a predetermined threshold temperature T (see Figure 4). The control unit 6 may initiate the forward movement of the plunger 3 immediately when the temperature exceeds the threshold temperature T, or it may initiate the forward movement of the plunger 3 after a predetermined time has elapsed since the temperature exceeded the threshold temperature T. Alternatively, instead of setting a threshold temperature, the control unit may initiate the forward movement of the plunger when the temperature rise within a relatively short predetermined period exceeds a predetermined temperature.

[0056] The control performed by the control unit based on the detection signal from the molten metal detection unit (see Figure 1) is not limited to the control of the injection cylinder. As another example, if an openable and closable shutter (not shown) is provided at the pouring port, the control unit may perform control such as closing the shutter after the pouring device stops pouring, based on the detection signal from the molten metal detection unit.

[0057] The threshold temperature T mentioned above is the temperature threshold detected by the molten metal detection unit 5. The threshold temperature T is set to a predetermined temperature that can only be reached when, during pouring, the oil level gradually rises to a height exceeding the upper surface 35a of the convex portion 35, which is the measurement range A of the molten metal detection unit 5. In other words, the threshold temperature T cannot be reached if there is no molten metal between the molten metal detection unit 5 and the upper surface 35a of the convex portion 35, and can only be reached if there is molten metal between the molten metal detection unit 5 and the upper surface 35a of the convex portion 35.

[0058] Referring to Figure 4, the relationship between the detected temperature [°C] of the molten metal detection unit 5 and the percentage of molten metal [%] in the injection sleeve 2 will be explained. As time passes from the start of pouring t0, the percentage of molten metal in the injection sleeve 2 gradually increases. At this time, the temperature of the plunger tip 30 rises slowly due to the molten metal in the injection sleeve 2. As a result, the temperature of the convex portion 35 also rises slowly, and the detected temperature of the molten metal detection unit 5 also rises slowly.

[0059] Then, as the oil level gradually rises, at point t1 when it reaches a height exceeding the upper surface 35a of the convex portion 35, the molten metal flows into the measurement range A of the molten metal detection unit 5. In this case, the molten metal detection unit 5 detects the temperature of the molten metal rather than the temperature of the upper surface 35a, causing the detected temperature of the molten metal detection unit 5 to rise rapidly and exceed the threshold temperature T.

[0060] For example, when the temperature detected by the molten metal detection unit 5 exceeds the threshold temperature T (i.e., a detection signal S is obtained from the molten metal detection unit 5), the control unit 6 triggers the stop of molten metal pouring by the pouring device, and the forward movement of the plunger 3 by the injection cylinder 1 begins as described above. The proportion of molten metal at the time the pouring by the pouring device stops is determined by the height position of the upper surface 35a of the convex portion 35.

[0061] Note that the above time point t1 is the point in the injection cylinder 1 after the initial ripple of the oil surface has subsided, and the oil surface is gradually rising to a level, flat surface. In Figure 4, t10 indicates the point in time when the initial ripple of the oil surface has largely subsided.

[0062] (Effects of the embodiment) The effects of this embodiment will be described.

[0063] In this embodiment, as described above, the plunger tip 30 and the injection through-hole 20 are formed in a non-circular shape that fits together when viewed from the direction of movement of the plunger 3. As a result, even if the contact resistance received from the injection sleeve 2 acts as a rotational force that rotates the plunger tip 30 when the plunger tip 30 slides inside the injection sleeve 2, the non-circular shape of the injection through-hole 20 that fits into the plunger tip 30 prevents the non-circular shape of the plunger tip 30 from rotating. Consequently, the rotation of the plunger rod 31 can be prevented.

[0064] In this embodiment, as described above, the plunger tip 30 and the injection through-hole 20 are formed in a non-circular shape that includes straight sections 30a, 20a and arc sections 30b, 20b, which fit together when viewed from the direction of movement. By making the shape of the plunger tip 30 and the injection through-hole 20 such that they are simply a circular shape with straight sections 30a, 20a added to it when viewed from the direction of movement, rotation of the plunger tip 30 can be prevented. Therefore, rotation of the plunger rod 31 can be easily prevented.

[0065] In this embodiment, as described above, a cooling water hose 4 is provided connected to the plunger rod 31 to supply cooling water to the plunger tip 30. The plunger tip 30 is provided with a cooling chamber R that is cooled by the cooling water. The plunger 3 includes an inlet channel 33 that introduces cooling water from the cooling water hose 4 into the cooling chamber R, and an outlet channel 34 that leads the cooling water from the cooling chamber R towards the plunger rod 31. The outlet channel 34 is positioned above the inlet channel 33. This prevents the plunger tip 30 from rotating and maintains a state in which cooling water is introduced from the inlet channel 33 on the lower side of the cooling chamber R and led out from the outlet channel 34 on the upper side of the cooling chamber R. As a result, the water level in the cooling chamber R can be maintained at a relatively high level, so that the plunger tip 30 can be effectively cooled.

[0066] In this embodiment, as described above, the straight sections 30a and 20a extend horizontally upward when viewed from the direction of movement, and the arc sections 30b and 20b are connected from below to both ends of the straight sections 30a and 20a when viewed from the direction of movement. As a result, the plunger tip 30 and the injection through-hole 20 are formed in a D shape by one straight section 30a and 20a and one arc section 30b and 20b, so that the simple shape of the plunger tip 30 and injection through-hole 20 can prevent the plunger tip 30 from rotating. Therefore, the simple shape of the plunger tip 30 and injection through-hole 20 can prevent the plunger rod 31 from rotating.

[0067] In this embodiment, as described above, the arc portions 30b and 20b have a central angle θ greater than 180 degrees such that the straight portions 30a and 20a are positioned above the center C2 of the arc portions 30b and 20b. This prevents the central angle θ of the arc portions 30b and 20b from being 180 degrees or less, thus avoiding the non-circular plunger tip 30 and the injection through hole 20 becoming elongated in the width direction. As a result, it is possible to suppress the unstable movement of the non-circular plunger tip 30 sliding inside the injection sleeve 2.

[0068] In this embodiment, as described above, in a direction perpendicular to the direction of movement, the central axis C1 of the plunger rod 31 is positioned on the opposite side of the center C2 of the arc portions 30b and 20b from the side where the straight portions 30a and 20a are located. This prevents the plunger rod 31 from being positioned biased towards the straight portions 30a and 20a, which are the edges of the plunger tip 30. As a result, the movement of the non-circular shaped plunger tip 30 sliding inside the injection sleeve 2 becomes more unstable.

[0069] In this embodiment, as described above, the plunger tip 30 includes a convex portion 35 that protrudes from the front surface 3a of the plunger 3 in the forward direction of the plunger 3. The convex portion 35 has a flat upper surface 35a and is equipped with a molten metal detection unit 5 that detects the relative position of the molten metal poured into the injection sleeve 2 with respect to the upper surface 35a. In the molding machine 100, the oil surface inside the injection sleeve 2 may become wavy in the initial stages of pouring, and this wavy surface gradually subsides as the oil surface rises. Therefore, by configuring it as described above, the amount of molten metal poured can be obtained by the molten metal detection unit 5 with respect to the upper surface 35a, so that the molten metal after the oil surface has risen can be detected, rather than the molten metal in the initial stages of pouring when the oil surface is wavy. Thus, the accuracy of obtaining the amount of molten metal can be suppressed from being reduced by the wavy surface of the oil during pouring.

[0070] (modified version) It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and further includes all modifications within the meaning and scope equivalent to the claims.

[0071] For example, in the above embodiment, an example was shown in which the molding machine 100 is configured as a die-casting machine, but the present invention is not limited thereto. In the present invention, the molding machine may be configured as an injection molding machine for molding resin.

[0072] Furthermore, although the above embodiment shows an example in which the molding machine 100 is configured as a so-called horizontal device in which the movable mold M2 moves laterally, the present invention is not limited to this. In the present invention, the molding machine may be configured as a so-called vertical device in which the movable mold moves vertically.

[0073] Furthermore, in the above embodiment, an example was shown in which the plunger tip 30 and the injection through-hole 20 are formed in a D-shape including one straight section 30a, 20a and one arc section 30b, 20b when viewed from the direction of movement, but the present invention is not limited to this. In the present invention, as shown in the modified molding machine 200 in Figure 5, the plunger tip 230 and the injection through-hole 220 may be formed in a shape in which four arc sections 230b, 220b are provided at the four corners of a rectangle formed by four straight sections 230a, 220a when viewed from the direction of movement.

[0074] Furthermore, although the above embodiment shows an example in which the molding machine 100 is equipped with only one sleeve (injection sleeve 2), the present invention is not limited thereto. In the present invention, the molding machine may be equipped with two sleeves, as shown in the modified molding machine 300 in Figure 6. In detail, the molding machine 300 is equipped with an injection sleeve 302 and a pouring sleeve 302a having a pouring port 321 that supplies molten metal into the injection sleeve 302. The pouring sleeve 302a has a cylindrical shape that extends in the vertical direction, and its lower end is in communication with the injection sleeve 302. In this molding machine 300, when the molten metal detection unit 5 detects molten metal while molten metal is being supplied from the pouring port 321, that is, when the control unit 306 obtains a detection signal S from the molten metal detection unit 5 indicating that the detected temperature is equal to or greater than the threshold temperature T (see Figure 4), the control unit 306 controls the movement of the plunger 3 by the injection cylinder 1 while continuing the pouring without stopping the pouring. A cylinder 302b is provided in the pouring sleeve 302a. The cylinder 302b is configured to push the molten metal remaining in the pouring sleeve 302a after injection into the injection sleeve 302 after the plunger 3 has retracted. In one example, the molten metal pushed into the injection sleeve 302 by the cylinder 302b is then discharged by the plunger 3 into the space between the fixed mold M1 and the movable mold M2.

[0075] In the modified example shown in Figure 6 above, the pouring sleeve 302a is positioned on the X2 side of the fixed die plate 101a, but the pouring sleeve may also be positioned between the fixed die plate and the fixed mold. In this case, the injection cylinder is formed to be relatively short in the X direction.

[0076] Furthermore, although the above embodiment shows an example in which the central angles of the arc portions 30b and 20b of the plunger tip 30 and the injection through-hole 20 are greater than 180 degrees, the present invention is not limited thereto. In the present invention, the central angles of the arc portions of the plunger tip and the injection through-hole may be 180 degrees or less.

[0077] Furthermore, in the above embodiment, an example was shown in which both the injection through-hole 20 of the injection sleeve 2 and the plunger tip 30 have straight sections 20a and 30a when viewed from the direction of movement of the plunger 3, but the present invention is not limited to this. In the present invention, both the injection through-hole of the injection sleeve and the plunger tip do not necessarily have straight sections. In this case, the injection through-hole of the injection sleeve and the plunger tip will have a shape that consists only of curved surfaces, such as an elliptical shape.

[0078] Furthermore, in the above embodiment, an example was shown in which both the injection through-hole 20 of the injection sleeve 2 and the plunger tip 30 have arc-shaped portions 20b and 30b when viewed from the direction of movement of the plunger 3, but the present invention is not limited to this. In the present invention, both the injection through-hole of the injection sleeve and the plunger tip do not have arc-shaped portions. In this case, the injection through-hole of the injection sleeve and the plunger tip are formed by at least one of a straight portion and a curved surface that is not an arc.

[0079] Furthermore, although the above embodiment shows an example in which the outlet channel 34 is placed directly above the inlet channel 33, the present invention is not limited to this. In the present invention, the outlet channel may be placed diagonally above the inlet channel, for example.

[0080] Furthermore, although the above embodiment shows an example in which the molten metal detection unit 5 is configured with a non-contact temperature sensor, the present invention is not limited thereto. In the present invention, the molten metal detection unit may be configured with a non-contact distance sensor. In this case, during pouring, the distance sensor can detect the height position of the oil surface that exceeds the upper surface of the convex portion. When the oil surface is lower than the upper surface of the convex portion, there is no change in the measurement value of the distance sensor. The control unit uses the change in the measurement value of the distance sensor, or the detection of an oil surface at a predetermined height after the measurement value of the distance sensor has started to change, as a trigger to perform predetermined control (such as control to start the forward movement of the plunger by the injection cylinder).

[0081] Furthermore, although the above embodiment shows an example in which the molten metal detection unit 5 is configured with a non-contact type temperature sensor that detects the temperature of the upper surface 35a of the convex portion 35, the present invention is not limited to this. In the present invention, the molten metal detection unit may be configured with a contact type temperature sensor. For example, the temperature sensor, which is the molten metal detection unit, may be configured with a thermocouple or the like, which is provided on the upper surface of the convex portion and detects the temperature of the upper surface of the convex portion.

[0082] Furthermore, in the above embodiment, an example was shown in which the central axis C1 of the plunger rod 31 is positioned on the opposite side of the arc sections 20a and 30a from the center C1 of the arc sections 20b and 30b, but the present invention is not limited to this. In the present invention, the central axis of the plunger rod may be positioned on the side of the arc section where the straight section is located, or near the center of the arc section, in a direction perpendicular to the direction of movement.

[0083] Furthermore, in the above embodiment, an example was shown in which the convex portion 35 is formed in a rectangular shape having a flat upper surface 35a when viewed from the direction of movement, but the present invention is not limited thereto. In the present invention, the convex portion may be formed in a shape other than a rectangle, such as a triangular shape having a flat upper surface, when viewed from the direction of movement. [Explanation of Symbols]

[0084] 2,302 injection sleeves 3 Plungers 3a front 4. Cooling water hose 5. Molten metal detection unit 20, 220 (Through holes for injection sleeves) 20a, 220a (Straight section of injection through hole) 20b, 220b Arc portion (of injection through hole) 30,230 plunger tips 30a, 230a (Plunger tip) straight section 30b, 230b (Plunger tip) Arc section 31 Plunger Rod 33 Inlet waterway 34 Outlet waterway 35 (The convex part of the plunger tip) 35a top surface 100, 200, 300 molding machine 101 Molding machine body C1 (the central axis of the plunger rod) C2 (center of the arc) M mold R Cooling Chamber θ (the central angle of the arc)

Claims

1. The molding machine body on which the mold is fixed, An injection sleeve provided in the molding machine body, including an injection through hole, The device comprises a plunger including a plunger tip that fits into the injection through hole of the injection sleeve, and a plunger rod, A molding machine in which the plunger tip and the injection through-hole are formed in a non-circular shape that fits together when viewed from the direction of movement of the plunger.

2. The molding machine according to claim 1, wherein the plunger tip and the injection through-hole are formed in a non-circular shape that includes a straight portion and an arc portion and fits together when viewed from the direction of movement.

3. The plunger rod is connected to a cooling water hose that supplies cooling water to the plunger tip, The plunger tip is provided with a cooling chamber that is cooled by cooling water. The plunger includes an inlet channel for introducing cooling water from the cooling water hose into the cooling chamber, and an outlet channel for leading the cooling water from the cooling chamber to the plunger rod side. The molding machine according to claim 1, wherein the outlet channel is located above the inlet channel.

4. The aforementioned straight section extends horizontally upward when viewed from the direction of movement. The molding machine according to claim 2, wherein the arc portion is connected from below to both ends of the straight portion when viewed from the direction of movement.

5. The molding machine according to claim 4, wherein the arc portion has a central angle greater than 180 degrees such that the straight portion is located above the center of the arc portion.

6. The molding machine according to claim 5, wherein, in a direction perpendicular to the direction of movement, the central axis of the plunger rod is positioned on the opposite side of the center of the arc portion from the side where the straight portion is located.

7. The plunger tip includes a convex portion that protrudes from the front surface of the plunger in the forward direction of the plunger, The convex portion has a flat upper surface, The molding machine according to claim 1, further comprising a molten metal detection unit for detecting the relative position of the molten metal poured into the injection sleeve with respect to the upper surface.

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