Molding machine

Abstract

The present invention provides a molding machine that can reduce the uneven load acting on the plunger tip that contacts the injection sleeve, thereby suppressing wear of the plunger tip. [Solution] This molding machine 100 comprises a molding machine body 101 to which a mold M is fixed, an injection sleeve 1 provided on the molding machine body 101, an injection cylinder 2 including a cylinder rod 20, a plunger tip 30 disposed inside the injection sleeve 1, a plunger rod 31 connected to the cylinder rod 20, and a plunger 3 including a movable connection mechanism 4 that connects the plunger rod 31 to the plunger tip 30 in a movable state.

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 cylinder.

Background Art

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

[0003] The above Patent Document 1 discloses a die casting machine including a plunger comprising a plunger tip and a plunger rod arranged in an injection sleeve, and an injection cylinder comprising a cylinder rod. The cylinder rod is connected to the plunger rod via a coupling. The plunger tip is detachably connected to the plunger rod via a connecting portion. By connecting the plunger tip to the plunger rod via the connecting portion, a state in which the central axes of the plunger tip and the plunger rod are aligned with each other (a state with no axis misalignment) is maintained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0005] However, in the die casting machine disclosed in the above Patent Document 1, the distal end side of the cylinder rod may sag downward due to the influence of the self-weight of the cylinder rod (so-called forward droop may occur). In this case, the portion of the plunger rod on the cylinder rod side also moves downward together and inclines, and further the plunger tip also receives a force that causes it to incline, so an eccentric load acts on the plunger tip that contacts the injection sleeve, which leads to the problem that the plunger tip is prone to wear.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide a molding machine that can reduce the uneven load acting on the plunger tip that contacts the injection sleeve and thereby suppress wear of the plunger tip. [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, an injection cylinder including a cylinder rod, a plunger tip disposed within the injection sleeve, a plunger rod connected to the cylinder rod, and a plunger including a movable connection mechanism that movably connects the plunger rod to the plunger tip.

[0008] In a molding machine according to one aspect of this invention, as described above, a movable connection mechanism is provided to connect the plunger rod, which is connected to the cylinder rod, to the plunger tip in a movable state. As a result, even if the tip of the cylinder rod moves downward and the cylinder rod side portion of the plunger rod also moves downward, the movable connection mechanism allows the plunger rod to move relative to the plunger tip, thereby suppressing the force that the plunger rod exerts on the plunger tip within the injection sleeve, which would otherwise cause it to tilt. In other words, the influence from the plunger rod to the plunger tip during so-called "front drop" can be mitigated. As a result, the uneven load acting on the plunger tip in contact with the injection sleeve can be reduced, thereby suppressing wear of the plunger tip.

[0009] In the molding machine according to the first aspect described above, preferably, the movable connection mechanism includes a first joint detachably fixed to the plunger tip and a second joint detachably fixed to the plunger rod, and is configured to movably connect the second joint fixed to the plunger rod to the first joint fixed to the plunger tip. With this configuration, the plunger rod can be easily connected to the plunger tip in a movable manner by the first joint and the second joint.

[0010] In this case, preferably, the movable connection mechanism includes a connecting member that connects the first joint and the second joint while limiting the range of movement of the second joint relative to the first joint to a predetermined range. With this configuration, the first joint and the second joint can be easily connected by the connecting member, and the range of movement of the second joint relative to the first joint can be limited to prevent excessive movement.

[0011] In the configuration in which the above-described movable connection mechanism includes a connecting member, preferably the connecting member has a cylindrical shape and is fixed to the first joint with the first and second joints positioned inside each other, thereby connecting the first and second joints while limiting the range of movement of the second joint relative to the first joint to a predetermined range. With this configuration, the connecting member can be fixed to the plunger tip via the first joint, so that the connecting member does not move relative to the plunger tip. As a result, it is possible to avoid the connecting member coming into contact with and getting caught in the plunger tip introduction opening of the injection sleeve.

[0012] In a configuration in which the above-described movable connection mechanism includes a first joint and a second joint, preferably, the movable connection mechanism is configured to connect the second joint, which is fixed to the plunger rod, to the first joint, which is fixed to the plunger tip, in a manner that allows movement in an orthogonal direction perpendicular to the central axis direction of the injection sleeve, and to connect the second joint, which is fixed to the plunger rod, to the first joint, which is fixed to the plunger tip, in a manner that allows tilting. With this configuration, even if the central axis of the plunger rod is shifted perpendicular to the central axis of the plunger tip, or if the central axis of the plunger rod is tilted relative to the central axis of the plunger tip, the eccentric load acting on the plunger tip that contacts the injection sleeve can be reduced, thereby suppressing wear of the plunger tip.

[0013] In the configuration in which the above-described movable connection mechanism includes a first joint and a second joint, preferably, the second joint is positioned at the boundary between the first joint and the second joint and has a convex arc surface projecting toward the first joint, and the first joint is positioned at the boundary between the first joint and the second joint and has a concave arc surface recessed along the convex arc surface, and the movable connection mechanism is configured to tilt the second joint, which is fixed to the plunger rod, relative to the first joint, which is fixed to the plunger tip, by rotating the convex arc surface along the concave arc surface. With this configuration, the second joint can be smoothly tilted by rotating the convex arc surface of the second joint along the concave arc surface of the first joint.

[0014] In this case, preferably, the movable connection mechanism includes a connecting member having a cylindrical shape and fixed to the first joint with the first and second joints positioned inside each other, thereby connecting the first and second joints while limiting the range of movement of the second joint relative to the first joint to a predetermined range. The connecting member is provided so as to circumferentially cover the second joint in an orthogonal direction perpendicular to the central axis direction of the injection sleeve, and is positioned with a first gap between it and the second joint, and has a first surface that limits the range of movement of the second joint in the orthogonal direction inside the connecting member to a first predetermined range; and a second surface that is provided so as to sandwich the second joint between it and the concave arc surface of the first joint in the central axis direction of the injection sleeve, and is positioned with a second gap between it and the second joint, and limits the range of movement of the second joint in the central axis direction inside the connecting member to a second predetermined range. With this configuration, the range of motion of the second joint can be restricted by the first and second surfaces to a first predetermined range in the orthogonal direction and a second predetermined range in the central axis direction, respectively. This allows the orientation of the plunger rod, to which the second joint is fixed, relative to the plunger tip, to which the first joint is fixed, to be restricted to a predetermined range. As a result, it is possible to avoid situations where the force from the cylinder is difficult or impossible to transmit from the plunger rod to the plunger tip due to the plunger rod bending significantly relative to the plunger tip or the plunger rod being significantly misaligned in the orthogonal direction relative to the plunger tip.

[0015] In the configuration in which the above movable connection mechanism includes a first joint and a second joint, it is preferable that a cooling water channel is provided on the plunger and supplies cooling water to the plunger tip, a hollow section is provided at the boundary between the second joint and the first joint, and the cooling water channel includes a first channel section provided on the plunger tip and formed by a through hole communicating with the hollow section, a second channel section provided on the plunger rod and formed by a through hole communicating with the hollow section, and a connecting channel section provided inside the hollow section and formed by a flexible tube that connects the first channel section and the second channel section. With this configuration, even when the second joint moves relative to the first joint, the connecting channel section, formed by a flexible tube that connects the first channel section and the second channel section, can maintain the connection between the first channel section and the second channel section. As a result, leakage of cooling water from the boundary between the second joint and the first joint can be suppressed.

[0016] In this case, preferably, the cooling water channel includes a first connector provided at one end of the connecting water channel section formed by a tube and connecting one end to the first water channel section, and a second connector provided at the other end of the connecting water channel section formed by a tube and connecting the other end to the second water channel section. With this configuration, the connecting water channel section can be easily connected to the first water channel section and the second water channel section by the first connector and the second connector.

[0017] In the molding machine according to the first aspect described above, preferably, the movable connection mechanism has an outer diameter smaller than the outer diameter of the plunger tip and is configured to be positioned inside the injection sleeve when the plunger is advanced during injection. With this configuration, the movable connection mechanism can be made relatively small so that it is positioned inside the injection sleeve during injection, thereby suppressing the uneven load acting on the plunger tip due to the weight of the movable connection mechanism. [Effects of the Invention]

[0018] According to the present invention, as described above, it is possible to provide a molding machine capable of reducing the eccentric load acting on the plunger tip in contact with the injection sleeve and suppressing wear of the plunger tip. [Brief Description of the Drawings]

[0019] [Figure 1] It is a diagram showing the overall configuration of the molding machine according to the embodiment. [Figure 2] It is a plan view showing the plunger including the movable connection mechanism in the neutral state of the molding machine according to the embodiment. [Figure 3] It is a side view showing the plunger including the movable connection mechanism in the neutral state of the molding machine according to the embodiment. [Figure 4] It is a plan view showing the movable connection mechanism when the plunger rod is positioned above the plunger tip of the molding machine according to the embodiment (when the introduction opening of the injection sleeve is lowered downward). [Figure 5] It is a plan view showing the movable connection mechanism when the plunger rod is positioned below the plunger tip of the molding machine according to the embodiment. [Figure 6] It is a plan view showing the movable connection mechanism when the plunger rod is inclined relative to the plunger tip of the molding machine according to the embodiment (when the front end of the injection cylinder sags downward). [Modes for Carrying Out the Invention]

[0020] (Embodiment) The configuration of the molding machine 100 according to the embodiment will be described with reference to FIG. 1 to FIG. 6.

[0021] In each figure, the direction in which the plunger tip 30 moves is indicated by the X direction. The direction in which the plunger tip 30 moves forward for injection is indicated by the X1 direction, and the opposite direction is indicated by the X2 direction. The X direction is also the direction of the central axis L extending from the injection sleeve 1 and the plunger tip 30, and is also the lateral direction that intersects the vertical direction. Furthermore, the X direction is also the direction of movement of the mold M (mold clamping and mold opening directions). In short, the molding machine 100 is a so-called horizontal type device in which the moving mold M2 moves laterally.

[0022] In each figure, the vertical direction is indicated by the Z direction. The upper part of the Z direction is indicated by the Z1 direction, and the lower part is indicated by the Z2 direction. The Z direction is also an orthogonal direction perpendicular to the central axis direction (X direction) to which the central axis L of the injection sleeve 1 extends.

[0023] In each figure, the direction perpendicular to the X and Z directions is indicated by the Y direction. That is, the depth direction of the molding machine 100 is indicated by the Y direction. The Y direction is also the orthogonal direction perpendicular to the central axis direction (X direction) to which the central axis L of the injection sleeve 1 extends. In short, the orthogonal direction is the radial direction of the injection sleeve 1.

[0024] (Configuration of the molding machine) The molding machine 100 shown in Figure 1 is a die-casting machine. In detail, the molding machine 100 is configured to form die-cast products by injecting molten metal into a cavity C of a mold M, which is composed of a fixed mold M1 and a movable mold M2, and allowing it to solidify within the cavity C. Examples of metal materials used for molding include aluminum alloys, zinc alloys, and magnesium alloys.

[0025] 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.

[0026] (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.

[0027] 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 1 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.

[0028] 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.

[0029] The tie bars 101c are a plurality of columnar members extending in the X direction, inserted through 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.

[0030] 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.

[0031] (Configuration of injection structure) As shown in Figure 1, the injection structure 102 comprises an injection sleeve 1, an injection cylinder 2, and a plunger 3. The plunger 3 includes a plunger tip 30, a plunger rod 31, and a movable connecting mechanism 4. The injection structure 102 also includes a cooling water channel 5 (see Figures 2 and 3) that supplies cooling water to the plunger tip 30.

[0032] In conventional molding machines, the plunger has a connecting member, such as a joint, that fixes and connects the plunger tip and the plunger rod to each other. This connecting member is configured to connect the plunger tip and the plunger rod by fixing them to each other while maintaining a concentric state in which the central axes of the plunger tip and the plunger rod coincide.

[0033] In this case, with conventional plungers, if the cylinder rod of the cylinder that drives the plunger sags downward due to its own weight (so-called "front drooping"), the cylinder-side portion of the plunger rod also sags downward (tilted). As a result, since the plunger tip and plunger rod are connected and fixed to each other by a connecting member, a force that causes the plunger tip to tilt is applied to the plunger tip fitted into the injection sleeve via the plunger rod and connecting member, resulting in an excessive load, or uneven load, acting on the plunger tip fitted into the injection sleeve. Such uneven load accelerates the wear of the plunger tip. It should be noted that the above-mentioned "front drooping" of the cylinder rod generally exists from the early stages of manufacturing the molding machine and gradually increases over time.

[0034] Therefore, in order to suppress the uneven load acting on the plunger tip 30, the plunger 3 of the molding machine 100 in this embodiment is configured such that the plunger rod 31 is movably connected to the plunger tip 30 by a movable connection mechanism 4. Details will be described later.

[0035] (Configuration of the injection sleeve in the injection structure) The injection sleeve 1 is formed in a cylindrical shape that extends laterally (in the X direction) and has a pouring port 10 that opens upwards into which molten metal is poured.

[0036] An injection opening 11 is provided at one end (X1 direction side) of the injection sleeve 1 for injecting molten metal into the mold M during injection. An introduction opening 12 is provided at the other end (X2 direction side) of the injection sleeve 1 for introducing the plunger tip 30 and the movable connection mechanism 4 into the inside of the injection sleeve 1. The plunger tip 30 is slidably fitted into the injection sleeve 1.

[0037] (Configuration of the cylinder in the injection structure) The injection cylinder 2 is configured to move the plunger 3 back and forth within the injection sleeve 1. In other words, the injection cylinder 2 is the drive source for the plunger 3. This drive source is either hydraulically driven or electrically driven. The injection cylinder 2 is located on the other side (X2 direction side) of the plunger 3. The injection cylinder 2 includes a cylinder rod 20 connected to the plunger rod 31 from the other side (X2 direction side) of the plunger rod 31. The plunger rod 31 and the cylinder rod 20 are connected by a coupling 6 such that their central axes are approximately aligned. The coupling 6 is formed to be slightly larger than the introduction opening 12 of the injection sleeve 1 and is not located inside the injection sleeve 1.

[0038] (Configuration of plunger 3 in the injection structure) As described above, the plunger 3 includes a plunger tip 30, a plunger rod 31, and a movable connection mechanism 4.

[0039] As shown in Figures 2 and 3, 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 slidably positioned within the injection sleeve 1. Inside the plunger tip 30 is a cooling chamber 30a for cooling the plunger tip 30. The plunger tip 30 is configured to be cooled by supplying cooling water to the cooling chamber 30a via a cooling water channel 5.

[0040] The plunger rod 31 has a columnar shape extending along the X direction. The plunger rod 31 is connected to the cylinder rod 20 (see Figure 1) at its X2 end by a coupling 6 (see Figure 1). The plunger rod 31 is configured to transmit the driving force of the injection cylinder 2 to the plunger tip 30.

[0041] (Configuration of the "movable connection mechanism 4" of the plunger 3 in the injection structure) The movable connection mechanism 4 includes a first joint 40, a second joint 41, and a connecting member 42.

[0042] The movable connection mechanism 4 has a circular outer surface at its outermost position. The movable connection mechanism 4 has an outer diameter smaller than the outer diameter of the plunger tip 30 and is configured to be positioned inside the injection sleeve 1 when the plunger 3 is advanced during injection. In this case, the entire movable connection mechanism 4 is positioned inside the injection sleeve 1. On the other hand, the coupling 6 (see Figure 1) that connects the plunger rod 31 and the cylinder rod 20 is always positioned outside the injection sleeve 1. In a cross-section perpendicular to the X direction, the movable connection mechanism 4 is formed to be thinner and smaller than the coupling 6.

[0043] (Regarding the first and second joints) The first joint 40 is detachably fixed to the plunger tip 30. The second joint 41 is detachably fixed to the plunger rod 31. The movable connection mechanism 4 is configured to movably connect the second joint 41, which is fixed to the plunger rod 31, to the first joint 40, which is fixed to the plunger tip 30. In one example, the first joint 40 and the second joint 41 are made of metal material.

[0044] The movable connection mechanism 4 is configured to connect the second joint 41, which is fixed to the plunger rod 31, to the first joint 40, which is fixed to the plunger tip 30, in a manner that allows movement in an orthogonal direction (radial direction of the injection sleeve 1) perpendicular to the central axis direction (X direction) of the injection sleeve 1. The plunger rod 31, connected to the plunger tip 30 by the movable connection mechanism 4, is movable in the orthogonal direction while maintaining its central axis approximately parallel to the central axis of the plunger tip 30.

[0045] Furthermore, the movable connection mechanism 4 is configured to connect the second joint 41, which is fixed to the plunger rod 31, to the first joint 40, which is fixed to the plunger tip 30, in a tiltable manner. In other words, the central axis of the plunger rod 31 connected to the plunger tip 30 by the movable connection mechanism 4 is tiltable with respect to the central axis of the plunger tip 30.

[0046] The first joint 40 is fixed to the plunger tip 30 from the other side (X2 direction side) of the plunger tip 30. For example, the first joint 40 is fixed to the plunger tip 30 by screwing. The first joint may also be fixed to the plunger tip by other means, such as press-fitting.

[0047] The first joint 40 has a large-diameter portion 40a and a small-diameter portion 40b, both having a cylindrical shape, which are positioned inside the connecting member 42. The diameter of the small-diameter portion 40b is smaller than the diameter of the large-diameter portion 40a. The central axes of the large-diameter portion 40a and the small-diameter portion 40b coincide with the central axis L of the injection sleeve 1.

[0048] The first joint 40 is positioned inside the connecting member 42, in a state where it abuts against the connecting member 42. More specifically, the first joint 40 is positioned in the X direction by the large-diameter portion 40a abutting against the annular inner surface 42a of the connecting member 42 from the X2 direction side. In addition, the first joint 40 is positioned in the Y and Z directions by at least one of the large-diameter portion 40a and the small-diameter portion 40b abutting against the inner circumferential surface (first surface 420a) of the connecting member 42.

[0049] A seal S1 is provided between the first joint 40 and the plunger tip 30 to prevent cooling water from leaking from inside the plunger 3. For example, the seal S1 is constructed with a labyrinth structure. Alternatively, the seal may be constructed with an O-ring or the like.

[0050] The first joint 40 is positioned at the boundary B between the first joint 40 and the second joint 41, and has a concave arc surface 400 that is recessed along the convex arc surface 410 of the second joint 41, which will be described later. The concave arc surface 400 is formed by a circular arc surface. For example, the center position of the circular arc surface forming the concave arc surface 400 is located on the central axis of the first joint 40.

[0051] The second joint 41 is fixed to the plunger rod 31 from one side of the plunger rod 31 (the side in the X1 direction). In one example, the second joint 41 is fixed to the plunger rod 31 by screwing. The second joint may also be fixed to the plunger rod by other means such as press-fitting.

[0052] The second joint 41 has a large-diameter portion 41a and a small-diameter portion 41b, both having a cylindrical shape, positioned inside the connecting member 42. The diameter of the small-diameter portion 41b is smaller than the diameter of the large-diameter portion 41a. In the neutral position, the central axes of the large-diameter portion 41a and the small-diameter portion 41b coincide with the central axis L of the injection sleeve 1.

[0053] The "neutral state" described above refers to a state in which the cylinder rod 20 (see Figure 1) does not exhibit the aforementioned drooping, and the central axis L of the injection sleeve 1 coincides with the central axes of the cylinder rod 20 and the plunger rod 31. In this neutral state, since the plunger rod 31 is not tilted, the plunger tip 30 is naturally not subjected to a load that would cause it to tilt away from the plunger rod 31.

[0054] The second joint 41 is positioned inside the connecting member 42 so as not to detach (come out) from the connecting member 42. In detail, the movement of the second joint 41 in the X2 direction is restricted by the large-diameter portion 41a of the second joint 41 contacting the annular protrusion 421 (second surface 421a) of the connecting member 42 (described later) from the X1 direction side. The movement of the second joint 41 in the X1 direction is restricted by the first joint 40. Furthermore, the movement of the second joint 41 in the orthogonal direction (radial direction of the injection sleeve 1) is restricted by the large-diameter portion 41a of the second joint 41 contacting the inner circumferential surface (first surface 420a) of the connecting member 42.

[0055] A seal S2 is provided between the second joint 41 and the plunger rod 31 to prevent cooling water from leaking from inside the plunger 3. For example, the seal S2 is constructed with a labyrinth structure. Alternatively, the seal may be constructed with an O-ring or the like.

[0056] The second joint 41 is positioned at the boundary B between the first joint 40 and the second joint 41, and has a convex arc surface 410 that protrudes along the concave arc surface 400 of the first joint 40. That is, the convex arc surface 410 protrudes toward the first joint 40. The convex arc surface 410 is formed by a circular arc surface. The curvature of the convex arc surface 410 of the second joint 41 is approximately the same as the curvature of the concave arc surface 400 of the first joint 40. As an example, the center position of the circular arc surface forming the convex arc surface 410 is located on the central axis of the second joint 41.

[0057] The movable connection mechanism 4 is configured to tilt the second joint 41, which is fixed to the plunger rod 31, relative to the first joint 40, which is fixed to the plunger tip 30, by rotating the convex arc surface 410 along the concave arc surface 400.

[0058] A hollow section 7 is provided at the boundary B between the second joint 41 and the first joint 40. The hollow section 7 spans the first joint 40, the second joint 41, and the plunger rod 31. The hollow section 7 is the internal space of the plunger 3 and is formed in a cylindrical shape extending in the X direction. A connecting water channel section 52, formed by a tube of the cooling water channel 5 (described later), is located in the hollow section 7. Since the second joint 41 is movable relative to the first joint 40, the portion of the hollow section 7 that spans the second joint 41 and the plunger rod 31 is movable relative to the portion of the hollow section 7 that is located on the first joint 40.

[0059] (Regarding connecting components) The connecting member 42 is configured to connect the first joint 40 and the second joint 41 while limiting the range of movement of the second joint 41 relative to the first joint 40 to a predetermined range. In one example, the connecting member 42 is made of a metal material.

[0060] In detail, the connecting member 42 has a cylindrical shape. The connecting member 42 is fixed to the first joint 40 with the first joint 40 and the second joint 41 positioned inside it, thereby connecting the first joint 40 and the second joint 41 while limiting the range of movement of the second joint 41 relative to the first joint 40 to a predetermined range. The connecting member 42 also serves as a cover member that covers the first joint 40 and the second joint 41 from the outside.

[0061] Therefore, since the connecting member 42 and the plunger tip 30 are fixed to each other via the first joint 40, they do not move relative to each other. As a result, even if the injection cylinder 2 (see Figure 1) sags, the position and orientation of the connecting member 42 relative to the introduction opening 12 of the injection sleeve 1 will not change.

[0062] The connecting member 42 is formed in a cylindrical shape by combining two arc-shaped members having a central angle of approximately 180 degrees when viewed from a direction along the central axis of the injection sleeve 1. The two arc-shaped members forming this connecting member 42 are positioned relative to each other by positioning pins inserted into positioning holes H1 (see Figure 2) with the first joint 40 and the second joint 41 in place, and are fixed to each other by bolts attached to bolt holes H2 (see Figure 2). By fixing the two arc-shaped members forming this connecting member 42 to each other, The first joint 40 is fixed to the connecting member 42 while the second joint 41 is movable inside the connecting member 42.

[0063] The connecting member 42 includes a cylindrical portion 420 extending in the X direction and a protrusion 421 projecting radially inward from the X2 end of the cylindrical portion 420.

[0064] The cylindrical portion 420 of the connecting member 42 has a first surface 420a that is provided to circumferentially cover the second joint 41 in a direction perpendicular to the central axis direction (X direction) of the injection sleeve 1. The first surface 420a is positioned with a first gap G1 between it and the second joint 41, and restricts the range of movement of the second joint 41 in the perpendicular direction inside the connecting member 42 to a first predetermined range R1 (the range shown by the white-painted arrow extending in the Z direction in Figure 3). In other words, the first surface 420a is a contact surface that abuts the second joint 41 from the outside in a direction perpendicular to it (radial direction). The corner portion of the second joint 41 that abuts the first surface 420a is chamfered with an R-chamfer or a C-chamfer.

[0065] The protrusion 421 of the connecting member 42 has a second surface 421a that is provided to sandwich the second joint 41 between itself and the concave arc surface 400 of the first joint 40 in the direction of the central axis of the injection sleeve 1. The second surface 421a is positioned with a second gap G2 between it and the second joint 41, and restricts the range of movement of the second joint 41 in the direction of the central axis inside the connecting member 42 to a second predetermined range R2 (the range shown by the white-painted arrow extending in the X direction in Figure 3). In other words, the second surface 421a is a contact surface that abuts the second joint 41 from the X2 radial side. The second gap G2 is also formed between the second joint 41 and the concave arc surface 400. The corner portion of the second joint 41 that abuts the second surface 421a is chamfered with an R-chamfer or C-chamfer.

[0066] (Regarding the movement of the second joint when the injection sleeve's entry opening is lowered) Referring to Figure 4, the movement of the second joint 41 relative to the first joint 40 when the introduction opening 12 of the injection sleeve 1 is lowered will be explained.

[0067] When the introduction opening 12 of the injection sleeve 1 is lowered (when the plunger rod 31 is positioned above the plunger tip 30), the second joint 41 is positioned slightly upward inside the connecting member 42. In this case, the central axis of the plunger tip 30 and the central axis of the plunger rod 31 are held approximately parallel. Also, the first gap G1 on the lower side of the second joint 41 becomes larger than the first gap G1 on the upper side of the second joint 41. The upward movement of the second joint 41 is restricted by the first surface 420a of the connecting member 42.

[0068] Thus, in the molding machine 100, the first joint 40 fixed to the plunger tip 30 does not move together with the second joint 41 fixed to the plunger rod 31. Instead, the second joint 41 moves upward relative to the first joint 40. Therefore, no force (a force that generates an uneven load on the plunger tip 30) acts from the second joint 41 to the first joint 40.

[0069] In other words, the molding machine 100, through the movable connection mechanism 4, mitigates the influence from the plunger rod 31 to the plunger tip 30 when the introduction opening 12 of the injection sleeve 1 is lowered. As a result, the molding machine 100, through the movable connection mechanism 4, reduces the eccentric load acting on the plunger tip 30 that contacts the injection sleeve 1.

[0070] (Regarding the movement of the second joint when the plunger rod is positioned above the plunger tip) Referring to Figure 5, the movement of the second joint 41 relative to the first joint 40 when the plunger rod 31 is positioned below the plunger tip 30 will be explained.

[0071] When the plunger rod 31 is positioned below the plunger tip 30, the second joint 41 is positioned slightly downward inside the connecting member 42. In this case, the central axis of the plunger tip 30 and the central axis of the plunger rod 31 are held approximately parallel. Also, the first gap G1 on the upper side of the second joint 41 becomes larger than the first gap G1 on the lower side of the second joint 41. The downward movement of the second joint 41 is restricted by the first surface 420a of the connecting member 42.

[0072] Thus, in the molding machine 100, the first joint 40 fixed to the plunger tip 30 does not move together with the second joint 41 fixed to the plunger rod 31. Instead, the second joint 41 moves downward relative to the first joint 40. Therefore, no force (a force that generates an uneven load on the plunger tip 30) acts from the second joint 41 to the first joint 40.

[0073] In other words, the molding machine 100, through the movable connection mechanism 4, mitigates the influence from the plunger rod 31 to the plunger tip 30 when the plunger rod 31 is positioned above the plunger tip 30. As a result, the molding machine 100, through the movable connection mechanism 4, reduces the eccentric load acting on the plunger tip 30 that contacts the injection sleeve 1.

[0074] (Regarding the movement of the second joint when a front flap is present) Referring to Figure 6, the movement of the second joint 41 relative to the first joint 40 when the cylinder rod 20 of the injection cylinder 2 (see Figure 1) is drooping will be explained.

[0075] If the cylinder rod 20 of the injection cylinder 2 is drooping, the portion of the plunger rod 31 on the cylinder rod 20 side will also move downward. That is, the plunger rod 31 and the second joint 41 are tilted so that the X2 direction side is lower than the X1 direction side. In this case, inside the connecting member 42, the convex arc surface 410 of the second joint 41 rotates along the concave arc surface 400 of the first joint 40 and moves upward. As a result, the first gap G1 on the lower side of the second joint 41 becomes larger than the first gap G1 on the upper side of the second joint 41. Also, the second gap G2 between the lower second surface 421a and the second joint 41 becomes larger than the second gap G2 between the upper second surface 421a and the second joint 41.

[0076] Thus, in the molding machine 100, the second joint 41 fixed to the plunger rod 31 is inclined relative to the first joint 40 fixed to the plunger tip 30, so no force (a force that generates an uneven load on the plunger tip 30) acts from the second joint 41 to the first joint 40.

[0077] In other words, the molding machine 100, through the movable connection mechanism 4, mitigates the effect from the plunger rod 31 to the plunger tip 30 during so-called front sagging. As a result, the molding machine 100, through the movable connection mechanism 4, reduces the eccentric load acting on the plunger tip 30 that contacts the injection sleeve 1.

[0078] (Cooling water channel configuration) The cooling water channel 5 is provided in the plunger 3. The cooling water channel 5 is configured to supply cooling water to the cooling chamber 30a of the plunger tip 30. The cooling water channel 5 is also configured to discharge cooling water from the cooling chamber 30a of the plunger tip 30. In other words, the cooling water channel 5 has a cooling water supply section 5a and a cooling water discharge section 5b. The supply section 5a and the discharge section 5b are arranged side by side at the same height.

[0079] As shown in Figures 2 and 3, the cooling water channel 5 includes a first channel section 50, a second channel section 51, and a connecting channel section 52.

[0080] The first water channel 50 is provided in the plunger tip 30 and the first joint 40 and is formed by a through hole that communicates with the hollow section 7. The end of the second water channel 51 on the X2 direction side communicates with the hollow section 7. The end of the first water channel 50 on the X1 direction side communicates with the cooling chamber 30a.

[0081] The second water channel 51 is provided on the plunger rod 31 and is formed by a through hole that communicates with the hollow section 7. The end of the second water channel 51 on the X1 direction side communicates with the hollow section 7. The end of the first water channel 50 of the supply section 5a on the X2 direction side is connected to a cooling water inlet pipe 53a that introduces cooling water into the plunger 3 from an external cooling water source (not shown) outside the plunger 3. The end of the first water channel 50 of the discharge section 5b on the X2 direction side is connected to a cooling water outlet pipe 53b that discharges cooling water from inside the plunger 3. Note that the cooling water inlet pipe 53a and the cooling water outlet pipe 53b are located outside the injection sleeve 1 when the plunger 3 is at its forward limit.

[0082] The connecting channel section 52 is provided inside the hollow section 7 and is formed by a flexible tube that connects the first channel section 50 and the second channel section 51. The connecting channel section 52 deforms when the first joint 40 moves relative to the second joint 41. As an example, the connecting channel section 52 is formed by a heat-resistant rubber tube.

[0083] Furthermore, the cooling water channel 5 includes a first connector 54a provided at one end 52a of the connecting water channel section 52 formed by a tube, and a second connector 54b provided at the other end 52b of the connecting water channel section 52 formed by a tube.

[0084] The first connector 54a is attached to the inner surface of the hollow section 7 on the X1 side and is configured to connect one end 52a of the connecting channel section 52 to the first channel section 50. The second connector 54b is attached to the inner surface of the hollow section 7 on the X2 side and is configured to connect the other end 52b of the connecting channel section 52 to the second channel section 51.

[0085] (Effects of the embodiment) The effects of this embodiment will be described.

[0086] In this embodiment, as described above, a movable connection mechanism 4 is provided to connect the plunger rod 31, which is connected to the cylinder rod 20, to the plunger tip 30 in a movable state. As a result, even if the tip of the cylinder rod 20 moves downward and the part of the plunger rod 31 on the cylinder rod 20 side also moves downward, the movable connection mechanism 4 allows the plunger rod 31 to move relative to the plunger tip 30, thereby suppressing the force that the plunger rod 31 exerts on the plunger tip 30 within the injection sleeve 1, which would otherwise cause the plunger tip 30 to tilt. In other words, the influence from the plunger rod 31 to the plunger tip 30 during so-called front sag can be mitigated. As a result, the uneven load acting on the plunger tip 30 that contacts the injection sleeve 1 can be reduced, thereby suppressing wear of the plunger tip 30.

[0087] In this embodiment, as described above, the movable connection mechanism 4 includes a first joint 40 detachably fixed to the plunger tip 30 and a second joint 41 detachably fixed to the plunger rod 31, and is configured to movably connect the second joint 41 fixed to the plunger rod 31 to the first joint 40 fixed to the plunger tip 30. This allows the plunger rod 31 to be easily connected to the plunger tip 30 in a movable manner by the first joint 40 and the second joint 41.

[0088] In this embodiment, as described above, the movable connection mechanism 4 includes a connecting member 42 that connects the first joint 40 and the second joint 41 while limiting the range of movement of the second joint 41 relative to the first joint 40 to a predetermined range. This makes it possible to easily connect the first joint 40 and the second joint 41 with the connecting member 42 and limit the range of movement of the second joint 41 relative to the first joint 40 to prevent excessive movement.

[0089] In this embodiment, as described above, the connecting member 42 has a cylindrical shape and is fixed to the first joint 40 with the first joint 40 and the second joint 41 positioned inside it. This configuration connects the first joint 40 and the second joint 41 while limiting the range of movement of the second joint 41 relative to the first joint 40 to a predetermined range. As a result, the connecting member 42 can be fixed to the plunger tip 30 via the first joint 40, preventing the connecting member 42 from moving relative to the plunger tip 30. Consequently, it is possible to avoid the connecting member 42 contacting and getting caught in the introduction opening 12 of the plunger tip 30 in the injection sleeve 1.

[0090] In this embodiment, as described above, the movable connection mechanism 4 is configured to connect the second joint 41, which is fixed to the plunger rod 31, to the first joint 40, which is fixed to the plunger tip 30, in a manner that allows movement in an orthogonal direction perpendicular to the central axis direction of the injection sleeve 1, and to connect the second joint 41, which is fixed to the plunger rod 31, to the first joint 40, which is fixed to the plunger tip 30, in a manner that allows tilting. As a result, in either the case where the central axis of the plunger rod 31 is shifted perpendicular to the central axis of the plunger tip 30, or where the central axis of the plunger rod 31 is tilted relative to the central axis of the plunger tip 30, the eccentric load acting on the plunger tip 30 that contacts the injection sleeve 1 can be reduced, thereby suppressing wear of the plunger tip 30.

[0091] In this embodiment, as described above, the second joint 41 is positioned at the boundary B between the first joint 40 and the second joint 41 and has a convex arc surface 410 that protrudes toward the first joint 40, the first joint 40 is positioned at the boundary B between the first joint 40 and the second joint 41 and has a concave arc surface 400 that is recessed along the convex arc surface 410, and the movable connection mechanism 4 is configured to tilt the second joint 41, which is fixed to the plunger rod 31, relative to the first joint 40, which is fixed to the plunger tip 30, by rotating the convex arc surface 410 along the concave arc surface 400. As a result, the second joint 41 can be smoothly tilted by rotating the convex arc surface 410 of the second joint 41 along the concave arc surface 400 of the first joint 40.

[0092] In this embodiment, as described above, the movable connection mechanism 4 has a cylindrical shape and is fixed to the first joint 40 with the first joint 40 and the second joint 41 positioned inside, thereby limiting the range of movement of the second joint 41 relative to the first joint 40 to a predetermined range, and includes a connecting member 42 that connects the first joint 40 and the second joint 41, the connecting member 42 is provided so as to circumferentially cover the second joint 41 in a direction perpendicular to the central axis direction of the injection sleeve 1, and the first joint 42 is provided between the second joint 41 and the first joint 41 It has a first surface 420a that is positioned with a gap G1 between it and the second joint 41, which restricts the range of movement of the second joint 41 in the orthogonal direction inside the connecting member 42 to a first predetermined range R1, and a second surface 421a that is provided in the direction of the central axis of the injection sleeve 1 so as to sandwich the second joint 41 between it and the concave arc surface 400 of the first joint 40, and is positioned with a second gap G2 between it and the second joint 41, which restricts the range of movement of the second joint 41 in the direction of the central axis inside the connecting member 42 to a second predetermined range R2. This allows the range of motion of the second joint 41 to be restricted by the first surface 420a and the second surface 421a to a first predetermined range R1 in the orthogonal direction and a second predetermined range R2 in the central axis direction, respectively. As a result, the position of the plunger rod 31 to which the second joint 41 is fixed relative to the plunger tip 30 to which the first joint 40 is fixed can be restricted to a predetermined range. Consequently, it is possible to avoid the cylinder force becoming difficult to transmit from the plunger rod 31 to the plunger tip 30, or not being transmitted at all, due to the plunger rod 31 bending significantly relative to the plunger tip 30 or the plunger rod 31 being significantly misaligned in the orthogonal direction relative to the plunger tip 30.

[0093] In this embodiment, as described above, the plunger 3 is provided with a cooling water channel 5 that supplies cooling water to the plunger tip 30, and a hollow section 7 is provided at the boundary B between the second joint 41 and the first joint 40. The cooling water channel 5 includes a first channel section 50 provided in the plunger tip 30 and formed by a through hole communicating with the hollow section 7, a second channel section 51 provided in the plunger rod 31 and formed by a through hole communicating with the hollow section 7, and a connecting channel section 52 provided inside the hollow section 7 and formed by a flexible tube that connects the first channel section 50 and the second channel section 51. As a result, even when the second joint 41 moves relative to the first joint 40, the connecting channel section 52, formed by a flexible tube that connects the first channel section 50 and the second channel section 51, can maintain the connection between the first channel section 50 and the second channel section 51. As a result, leakage of cooling water from the boundary B between the second joint 41 and the first joint 40 can be suppressed.

[0094] In this embodiment, as described above, the cooling water channel 5 includes a first connector 54a provided at one end 52a of the connecting water channel section 52 formed by a tube, which connects one end 52a to the first water channel section 50, and a second connector 54b provided at the other end 52b of the connecting water channel section 52 formed by a tube, which connects the other end 52b to the second water channel section 51. This allows the connecting water channel section 52 to be easily connected to the first water channel section 50 and the second water channel section 51 by the first connector 54a and the second connector 54b.

[0095] In this embodiment, as described above, the movable connection mechanism 4 has an outer diameter smaller than the outer diameter of the plunger tip 30 and is configured to be positioned inside the injection sleeve 1 when the plunger 3 is advanced during injection. This allows the movable connection mechanism 4 to be made relatively small so that it is positioned inside the injection sleeve 1 during injection, thereby suppressing the uneven load acting on the plunger tip 30 due to the weight of the movable connection mechanism 4.

[0096] (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.

[0097] 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.

[0098] Furthermore, although the above embodiment shows an example in which the first channel 50 is provided in both the first joint 40 and the plunger tip 30, the present invention is not limited thereto. In the present invention, the first channel may be provided only in the plunger tip. In this case, the hollow portion is provided so as to span both the first joint and the plunger tip.

[0099] Furthermore, although the above embodiment shows an example in which the second channel 51 is provided only on the plunger rod 31, the present invention is not limited thereto. In the present invention, the second channel may be provided on both the second joint and the plunger tip. In this case, the hollow portion is provided on the second joint but not on the plunger tip.

[0100] Furthermore, although the above embodiment shows an example in which the first joint 40 is fixed to the connecting member 42 of the movable connection mechanism 4, the present invention is not limited to this. In the present invention, a second joint may be fixed to the connecting member of the movable connection mechanism instead of the first joint.

[0101] Furthermore, as described above, when the second joint is fixed to the connecting member of the movable connection mechanism instead of the first joint, the convex arc surface may be provided on the first joint instead of the second joint, and the concave arc surface may be provided on the second joint instead of the first joint.

[0102] Furthermore, although the above embodiment shows an example in which the opposing surfaces of the first joint 40 and the second joint 41 are formed by curved surfaces (convex curved surface 410, concave curved surface 400), the present invention is not limited thereto. In the present invention, the opposing surfaces of the first joint and the second joint may be formed by flat surfaces.

[0103] Furthermore, although the above embodiment shows an example in which the first joint 40 and the plunger tip 30 are detachable and separate components, the present invention is not limited to this. In the present invention, the first joint and the plunger tip may be an integrated component. In this case, the total number of joints provided by the movable connection mechanism will be one. However, the total number of joints provided by the movable connection mechanism may be three or more.

[0104] Furthermore, although the above embodiment shows an example in which the second joint 41 and the plunger rod 31 are detachable and separate components, the present invention is not limited to this. In the present invention, the second joint and the plunger rod may be an integrated component. In this case, the total number of joints provided by the movable connection mechanism will be one. However, the total number of joints provided by the movable connection mechanism may be three or more.

[0105] Furthermore, although the above embodiment shows an example in which the supply portion 5a and the discharge portion 5b of the cooling water channel 5 are arranged side by side at the same height, the present invention is not limited to this. In the present invention, the supply portion and the discharge portion of the cooling water channel may be arranged vertically.

[0106] Furthermore, although the above embodiment shows an example in which the movable connection mechanism 4 is provided with a connecting member 42, the present invention is not limited thereto. In the present invention, the movable connection mechanism does not need to be provided with a connecting member. In this case, for example, the shape of the first joint may be a combination of the shape of the first joint in the above embodiment and the shape of the connecting member in the above embodiment. [Explanation of Symbols]

[0107] 1. Injection sleeve 2 Injection Cylinder 3 Plungers 4. Movable connection mechanism (of the plunger) 5 Cooling channel 7 Hollow part 20 Cylinder rod (of the injection cylinder) 30 (plunger) plunger tips 31 (plunger) plunger rod 40 (First joint of the movable connection mechanism) 41 (Second joint of the movable connection mechanism) 42 Connecting member (of movable connection mechanism) 50 (First channel section of the cooling water channel) 51 Second channel section (of the cooling water channel) 52 (Cooling water channel) Connecting water channel section 52a (One end of the connecting channel section) 52b (other end of connecting channel) 54a First connector (of the cooling water channel) 54b Second connector (of the cooling water channel) 100 molding machine 101 Molding machine body 400 (Concave arc surface of the first joint) 410 Convex curved surface (of the second joint) 420a First surface (of the connecting member) 421a Second surface (of the connecting member) B boundary G1 First gap G2 Second Gap M mold R1 First predetermined range R2 Second predetermined range

Claims

1. The molding machine body on which the mold is fixed, The injection sleeve provided on the molding machine body, An injection cylinder including a cylinder rod, A molding machine comprising a plunger including a plunger tip disposed within the injection sleeve, a plunger rod connected to the cylinder rod, and a movable connection mechanism that movably connects the plunger rod to the plunger tip.

2. The molding machine according to claim 1, wherein the movable connection mechanism includes a first joint detachably fixed to the plunger tip and a second joint detachably fixed to the plunger rod, and is configured to movably connect the second joint fixed to the plunger rod to the first joint fixed to the plunger tip.

3. The molding machine according to claim 2, wherein the movable connection mechanism includes a connecting member that connects the first joint and the second joint while limiting the range of movement of the second joint relative to the first joint to a predetermined range.

4. The molding machine according to claim 3, wherein the connecting member has a cylindrical shape and is fixed to the first joint with the first joint and the second joint positioned inside it, thereby connecting the first joint and the second joint while limiting the range of movement of the second joint relative to the first joint to the predetermined range.

5. The aforementioned movable connection mechanism is The second joint, fixed to the plunger rod, is connected to the first joint, fixed to the plunger tip, in such a manner that it can move in an orthogonal direction perpendicular to the central axis direction of the injection sleeve. The molding machine according to claim 2, wherein the second joint, fixed to the plunger rod, is connected to the first joint, fixed to the plunger tip, in a tiltable manner.

6. The second joint is positioned at the boundary between the first joint and the second joint and has a convex arc surface that protrudes toward the first joint. The first joint is positioned at the boundary between the first joint and the second joint and has a concave arc surface that is recessed along the convex arc surface, The molding machine according to claim 2, wherein the movable connection mechanism is configured to tilt the second joint, which is fixed to the plunger rod, relative to the first joint, which is fixed to the plunger tip, by rotating the convex arc surface along the concave arc surface.

7. The movable connection mechanism includes a connecting member that has a cylindrical shape and is fixed to the first joint with the first and second joints positioned inside each other, thereby connecting the first and second joints while limiting the range of movement of the second joint relative to the first joint to a predetermined range. The aforementioned connecting member is In a direction perpendicular to the central axis direction of the injection sleeve, the connecting member is provided so as to circumferentially cover the second joint and is positioned with a first gap between it and the second joint, and has a first surface that limits the range of movement of the second joint in the perpendicular direction within the connecting member to a first predetermined range, The molding machine according to claim 6, wherein the injection sleeve has a second surface provided in the direction of the central axis of the first joint so as to sandwich the second joint between the first joint and the concave arc surface of the first joint, and is positioned with a second gap between it and the second joint, and the second surface restricts the range of movement of the second joint in the direction of the central axis inside the connecting member to a second predetermined range.

8. The plunger is provided with a cooling water channel that supplies cooling water to the plunger tip, A hollow portion is provided at the boundary between the second joint and the first joint. The aforementioned cooling water channel is A first water channel is provided in the plunger tip and is formed by a through hole communicating with the hollow portion, A second water channel is provided on the plunger rod and is formed by a through hole that communicates with the hollow portion, The molding machine according to claim 2, further comprising a connecting water channel section provided inside the hollow section and formed by a flexible tube that connects the first water channel section and the second water channel section.

9. The aforementioned cooling water channel is A first connector is provided at one end of the connecting water channel section formed by the tube, and connects the one end to the first water channel section. The molding machine according to claim 8, further comprising: a second connector provided at the other end of the connecting water channel portion formed by the tube, and connecting the other end to the second water channel portion.

10. The molding machine according to claim 1, wherein the movable connecting mechanism has an outer diameter smaller than the outer diameter of the plunger tip and is configured to be positioned inside the injection sleeve when the plunger is advanced during injection.

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