Molding device

Abstract

To provide a mold clamping device capable of suppressing the generation of unexpected stress on a mold, even when a single large mold is mounted straddling two mold clamping devices.SOLUTION: A mold clamping device (10) includes a first fixed platen (11A) and a second fixed platen (11B), a first movable platen (13A) corresponding to the first fixed platen (11A) and a second movable platen (13B) corresponding to the second fixed platen (11B), and one or both of a fixed side connector (41) that connects the first fixed platen (11A) and the second fixed platen (11B) and a movable side connector (43) that connects the first movable platen (13A) and the second movable platen (13B).SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a mold clamping device used in a two - unit injection molding machine in which two injection molding machines are arranged in parallel.

Background Art

[0002] A two - unit injection molding machine is disclosed in Patent Document 1, in which two injection molding machines are arranged in parallel, and the mold clamping devices of these injection molding machines are configured to operate in联动 by mechanical connection or electrical control, so that the mutual mold clamping devices can be selectively used according to the size of the mold, improving the machine operation rate and productivity. When using a large - sized mold that straddles the movable plates of two adjacent injection molding machines in the two - unit injection molding machine of Patent Document 1, the mold is attached to the movable plates and fixed plates of the other side, and two mold clamping devices (the first mold clamping device, the second mold clamping device) are mechanically coupled to operate in联动 with each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to Patent Document 1, although the opening and closing operations of the movable plates can be联动, the molds are only straddled and connected to the fixed plates and movable plates of two adjacent individual injection molding machines respectively. However, if the positions of the fixing plates of the first and second clamping devices do not precisely coincide during installation, specifically in the direction of mold opening and closing perpendicular to the width direction of the fixing plates, the mold mounting surfaces of the fixing plates of the first and second clamping devices will be misaligned with the adjacent mold mounting surface, creating a step. This step creates a gap between the mold and the mold plates when a large mold is mounted spanning both plates, resulting in unstable mold fixation. Furthermore, because the mold and mold plates are not in close contact in this gap, unexpected bending stress may occur in the mold during clamping, potentially leading to mold damage or failure. Furthermore, during mold clamping, the mold plate flexes, causing it to be pulled in the width direction (horizontal direction). This causes the fixed plate of the first and second mold clamping devices to move away from each other. However, because the fixed plate of the first and second mold clamping devices are not mechanically connected, the stress lines cannot connect the two mold plates and instead flow into the mold. As a result, the stress lines of the horizontal tensile stress caused by the flexure of the mold plate pass through the mold. In other words, there is a risk of unexpected tensile stress in the width direction being generated in the mold. Therefore, the present invention aims to provide a mold clamping device that can suppress the generation of unexpected stress on a mold even when a single large mold is mounted across two mold clamping devices. [Means for solving the problem]

[0005] The clamping device of the present invention is First fixed panel and second fixed panel, A first movable plate corresponding to the first fixed platen and a second movable plate corresponding to the second fixed platen, A fixed-side connecting body that connects the first fixed platen and the second fixed platen, and It includes one or both of the movable side connecting members that connect the first movable platen and the second movable platen.

[0006] In a clamping device, preferably, The first fixed panel has a first opposing surface, and the second fixed panel has a second opposing surface. The first movable platen has a third opposing surface facing the first opposing surface, and the second movable platen has a fourth opposing surface facing the second opposing surface. A preferred clamping device is: A fixed-side connecting body that spans the first opposing surface and the second opposing surface, connecting the first fixed platen and the second fixed platen, and It includes one or both of the movable side connecting members that span across the third and fourth opposing surfaces and connect the first and second movable plates.

[0007] In a preferred clamping device, The fixed-side connector is It is fixed to the first and second fixed plates in a way that allows for easy attachment and detachment. The movable connector is It is fixed to the first and second movable plates in a way that allows for easy attachment and removal.

[0008] In a clamping device, preferably, A fixed-side intermediate body is provided between the fixed-side connector and the first fixed platen and the second fixed platen, It comprises a movable side connecting body and a movable side intermediate body provided between the first movable platen and the second movable platen.

[0009] The stationary intermediate is preferably, The fixed-side connector is slidable relative to the first fixed platen and the second fixed platen, or The fixed-side connector has lower rigidity than the first fixed plate and the second fixed plate. The movable intermediate body is preferably, The movable side connector is slidable relative to the first movable platen and the second movable platen, or It has lower rigidity than the movable side connector, the first movable platen, and the second movable platen. [Effects of the Invention]

[0010] According to the present invention, the system comprises either a fixed-side connector or a movable-side connector, or both. Even when a large mold is mounted across two mold clamping devices, it is possible to suppress the generation of unexpected stress on the mold. [Brief explanation of the drawing]

[0011] [Figure 1] It is a plan sectional view showing the basic configuration of an injection molding machine to which the present invention is applied. [Figure 2] It is a plan sectional view showing a mold clamping device according to the first embodiment. [Figure 3] It is a view seen from the opposing surface of the mold clamping device in FIG. 2. [Figure 4] It is a view for explaining the effect of the mold clamping device according to the first embodiment. [Figure 5] It is a plan sectional view showing the state before mold clamping of a mold clamping device according to the second embodiment. [Figure 6] It is a plan sectional view showing the mold clamping state of a mold clamping device according to the second embodiment. [Figure 7] It is a plan sectional view showing a mold clamping device according to the third embodiment. [Figure 8] It is a plan sectional view showing a mold clamping device according to the fourth embodiment. [Figure 9] It is a plan sectional view showing the state before mold clamping of a mold clamping device according to the fifth embodiment. [Figure 10] It is a plan sectional view showing the mold clamping state of a mold clamping device according to the fifth embodiment. [Figure 11] It is a view for explaining the stress state of the mold clamping device according to the basic configuration. [Figure 12] It is a view for explaining the mold clamping state of the mold clamping device according to the basic configuration. [Figure 13] It is a view showing a modified example of a fixed-side connecting body (movable-side connecting body). [Figure 14] It is a view showing an arrangement example of a fixed-side connecting body (movable-side connecting body).

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description will first explain the basic configuration applied to this embodiment and then explain more specific embodiments.

[0013] 〔Basic Configuration: Refer to FIG. 1〕 The basic configuration of the injection molding machine 100 includes a clamping device 10 and an injection device 30 that injects molten resin into one mold 50 that is clamped by the clamping device 10. In the injection molding machine 100, one mold 50 is clamped by two clamping devices 10. The horizontal direction H and the vertical direction V are defined as shown in Figure 1, and the length direction L and width direction W in the injection molding machine 100 are defined as shown in Figure 1.

[0014] [Clamping device 10: See Figure 1] The clamping device 10 consists of a first clamping device 10A and a second clamping device 10B, which are arranged in parallel in the horizontal direction H. Although the arrangement of the first clamping device 10A and the second clamping device 10B is different, they have the same configuration, including dimensions. Therefore, the configuration of the first clamping device 10A will be described below, but for the second clamping device 10B, the same reference numerals as those used for the first clamping device 10A will be used for the same components as the first clamping device 10A, and the description will be omitted.

[0015] The first mold clamping device 10A comprises a first fixed platen 11A on which a fixed mold 51 is supported, and a first movable platen 13A on which a movable mold 53 is supported. The second mold clamping device 10B comprises a second fixed platen 11B on which a fixed mold 51 is supported, and a second movable platen 13B on which a movable mold 53 is supported. The first fixed platen 11A and the second fixed platen 11B are installed on a base (not shown) and their positions are fixed, while the first movable platen 13A and the second movable platen 13B are supported, for example, on guide rails that are laid on the base so as to be able to move forward (F) and backward (R).

[0016] The first clamping device 10A includes a clamping hydraulic chamber 18 for applying a load for clamping the mold 50 via the first fixed platen 11A and the first movable platen 13A. The clamping hydraulic chamber 18 is located at the four corners of the first fixed platen 11A when viewed from the front. The clamping hydraulic chamber 18 houses a ram 16 provided at the front (F) end of the tie bar 17, so that the clamping side chamber 18A is located at the rear (R) and the mold opening side chamber 18B is located at the front (F) with the ram 16 as the boundary. A hydraulic power source (not shown) is connected to the clamping side chamber 18A and the mold opening side chamber 18B, and hydraulic fluid is supplied to the clamping side chamber 18A when clamping and to the mold opening side chamber 18B when opening.

[0017] The ram 16 is movable forward and backward within the clamping hydraulic chamber 18, and a tie bar 17 is connected to one side of it. The tie bar 17 penetrates the first movable platen 13A, and multiple ring grooves (male threads) of equal or unequal pitch (not shown) are formed at its rear (R) end. A split nut 19 is provided on the rear (R) end face of the first movable platen 13A, which has a ring-shaped inner groove (female thread) that engages with the ring grooves (male threads) of the tie bar 17. When hydraulic fluid is supplied to the clamping side chamber 18A, the hydraulic fluid in the clamping side chamber 18A pushes the ram 16 forward (F), so the tie bar 17 receives a forward (F) tensile load. Since the split nut 19 is provided on the rear (R) of the first movable platen 13A, the first movable platen 13A receives the forward (F) tensile load generated on the tie bar 17 via the split nut 19 that engages with the tie bar 17. In this way, the mold clamping is performed by pressing the movable mold 53 toward the fixed mold 51.

[0018] The configuration and clamping operation of the first clamping device 10A described above also apply to the second clamping device 10B.

[0019] [Injection device 30: See Figure 1] The injection molding machine 100 forms a molded product by injecting molten resin into the cavity formed between the fixed mold 51 and the movable mold 53 after the mold clamping is complete. The injection molding machine 100 is equipped with an injection device 30 for this purpose, but here only the two injection barrels 31 for injecting the molten resin are drawn away from the first clamping device 10A and the second clamping device 10B.

[0020] [Mold 50: See Figure 1] The mold 50 comprises a fixed mold 51 and a movable mold 53. The fixed mold 51 is supported by the first fixed platen 11A of the first mold clamping device 10A and the second fixed platen 11B of the second mold clamping device 10B. The movable mold 53 is supported by the first movable platen 13A of the first mold clamping device 10A and the second movable platen 13B of the second mold clamping device 10B. In other words, the fixed mold 51 is supported by being spanned between the first fixed platen 11A and the second fixed platen 11B, and the movable mold 53 is supported by being spanned between the first movable platen 13A and the second movable platen 13B. In addition, one mold 50 is supported by two first mold clamping devices 10A and two second mold clamping devices 10B. The fixed mold 51 and the movable mold 53 are made of steel materials referred to as plastic mold steel. Specifically, pre-hardened steel such as JIS SC series, SCM series, and SKD61, hardened and tempered steel such as JIS SKD11 and SKD12, stainless steel such as JIS SUS420J2 and SUS630, and maraging steel are used as plastic mold steel. In addition, while cast iron such as spheroidal graphite cast iron or gray cast iron is generally used for the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B, the same steel material as that used for the fixed mold 51 and the movable mold 53 may also be used.

[0021] [First embodiment: See Figures 2 and 3] The clamping device 10-1 according to the first embodiment follows the basic configuration of the clamping device 10 and includes a mold connector 40. The mold connector 40 comprises a fixed-side connector 41 provided on the side of the first fixed platen 11A and the second fixed platen 11B, and a movable-side connector 43 provided on the side of the first movable platen 13A and the second movable platen 13B. The fixed-side connector 41 is fixed by being spanned between the first opposing surface 11C of the first fixed platen 11A and the first movable platen 13A, and the second opposing surface 11D of the second fixed platen 11B and the second movable platen 13B. The movable-side connector 43 is fixed by being spanned between the third opposing surface 13C of the first fixed platen 11A and the fourth opposing surface 13D of the second movable platen 13B. The fixed-side connector 41 covers the first opposing surface 11C and the second opposing surface 11D, except for the portion of the tie bar 17. The movable-side connector 43 covers the third opposing surface 13C and the fourth opposing surface 13D, except for the portion of the tie bar 17. The fixed connector 41 and the movable connector 43 are fixed to the first fixed platen 11A and the second fixed platen 11B, and the first movable platen 13A and the second movable platen 13B, respectively, by fasteners 49.

[0022] In this embodiment, it is not always necessary to use a large mold that spans both the first and second clamping devices 10A and 10B. In this case, the first opposing surface 11C and the second opposing surface 11D may each be capable of mounting individual molds with the fixed-side connector 41 removed, and the third opposing surface 13C and the fourth opposing surface 13D may each be capable of mounting individual molds with the movable-side connector 43 removed. This allows the two first and second clamping devices 10A and 10B to operate independently of each other, enabling molding operations with individual molds. In this case, the fixing means for fixing the fixed-side connector 41 and the movable-side connector 43 to the first fixed platen 11A and the second fixed platen 11B, and the first movable platen 13A and the second movable platen 13B, respectively, is preferably a fixing means that detachably fixes the fixed-side connector 41 and the movable-side connector 43 to the first fixed platen 11A and the second fixed platen 11B, and the first movable platen 13A and the second movable platen 13B, respectively. In this case, it is preferable that the first opposing surface 11C and the second opposing surface 11D are positioned to facilitate the attachment and detachment of the fixed-side connector 41, and the third opposing surface 13C and the fourth opposing surface 13D are positioned to facilitate the attachment and detachment of the movable-side connector 43. The positioning process may be a positioning pin process, or a groove process that allows for precise fitting.

[0023] The fixed mold 51 of the mold 50 is fixed to the first fixed platen 11A and the second fixed platen 11B by appropriate means via the fixed-side connector 41. The movable mold 53 of the mold 50 is fixed to the first movable platen 13A and the second movable platen 13B by appropriate means via the movable-side connector 43. The fixed mold 51 and the movable mold 53 are attached to the fixed-side connector 41 and the movable-side connector 43 so that they are in positions that coincide with each other. In this way, the fixed-side connector 41 and the movable-side connector 43 can be referred to as the fixed-side mounting body and the movable-side mounting body, respectively, since the fixed mold 51 and the movable mold 53 are attached to them.

[0024] The fixed-side connector 41 and the movable-side connector 43 may be made of cast iron, similar to the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B, or they may be made of steel, similar to the fixed mold 51 and the movable mold 53. However, it is preferable that the fixed-side connector 41 and the movable-side connector 43 be made lighter by having a thinner wall thickness than the first fixed platen 11A to the second movable platen 13B in order to reduce the overall weight including the first fixed platen 11A to the second movable platen 13B.

[0025] [Effects of the first embodiment (mold assembly): See Figures 4, 11, and 12] The effects of providing a mold connector 40 when supplying hydraulic fluid to the clamping side chamber 18A of the clamping hydraulic chamber 18 to clamp the fixed mold 51 and the movable mold 53 will be explained.

[0026] <Stress state in the first embodiment: Figures 4 and 11> When the molds are clamped, tensile stress is generated in each tie bar 17 in the axial direction, and the ends of the first fixed platen 11A and the first movable platen 13A in the width direction W, which are not sandwiched by the mold 50 and are not backed up by the mold 50, deflect toward each other, and the ends of the second fixed platen 11B and the second movable platen 13B in the width direction W also deflect toward each other. Due to this deflection, the first fixed platen 11A and the second fixed platen 11B and the first movable platen 13A and the second movable platen 13B are pulled toward each other in the direction of separation (width direction W), so that tensile stress σi is generated inside the first fixed platen 11A and the second fixed platen 11B and the first movable platen 13A and the second movable platen 13B (Figure 11). Figure 4 shows the stress line Lσ due to the tensile stress σi. However, since the first fixed platen 11A and the second fixed platen 11B, and the first movable platen 13A and the second movable platen 13B are not directly connected, the stress line Lσ passes through the fixed-side connector 41 and the movable-side connector 43, i.e., the mold connector 40, at adjacent parts of the first fixed platen 11A and the second fixed platen 11B, and the first movable platen 13A and the second movable platen 13B.

[0027] <Stress state in the basic configuration: Figure 11> Here, the stress line Lσ when the mold clamping device 10 in the basic configuration without the mold connector 40 is clamped is as shown in Figure 11. In other words, because the first fixed platen 11A and the second fixed platen 11B are not connected and there is a gap G1, the stress line Lσ cannot directly communicate from the first fixed platen 11A to the second fixed platen 11B and passes through the inside of the fixed mold 51. Normally, molds are not designed assuming that tensile stress will act in the width direction, so there is a risk that tensile stress in an unexpected direction will occur in the fixed mold 51. If injection molding is repeatedly performed using the fixed mold 51, the possibility that the fixed mold 51 will fatigue and break cannot be ruled out. In contrast, if the mold connector 40 is provided, the stress line Lσ passes through the mold connector 40, so no unexpected stress occurs in the fixed mold 51. The same applies to the movable mold 53.

[0028] <Positional misalignment in the basic configuration: Figure 12> Other concerns regarding the basic configuration of the clamping device 10 will be explained based on Figure 12. The concern is that the position of the first fixing platen 11A of the first clamping device 10A and the position of the second fixing platen 11B of the second clamping device 10B do not coincide, resulting in a misalignment G2. When this misalignment G2 occurs, a misalignment also occurs between the first opposing surface 11C of the first fixing platen 11A and the second opposing surface 11D of the second fixing platen 11B. In this case, a gap G3 is created between the fixed mold 51 and the second fixing platen 11B, making the fixing of the fixed mold 51 unstable. Alternatively, unexpected bending may occur in the fixed mold 51 during clamping, potentially leading to damage or failure of the fixed mold 51.

[0029] In contrast, by providing the mold connector 40, the positions of the first fixed platen 11A and the second fixed platen 11B can be corrected, preventing misalignment G2 and gap G3 from occurring. Furthermore, the fixed-side connector 41 and the movable-side connector 43 are fixed to the first fixed platen 11A and the second fixed platen 11B, and the first movable platen 13A and the second movable platen 13B, respectively, by fasteners 49. At this time, it is preferable to fix the mold connector 40 to the first fixed platen 11A and the second fixed platen 11B, and then fix the mold connector 40, the first fixed platen 11A, and the second fixed platen 11B to their bases after integrating them. This allows the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B to their bases using the mold connector 40 as a reference, making it easier to fix the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B to their bases without causing misalignment G2 and gaps G3.

[0030] In this case, there is a preferred arrangement of the fixed-side connector 41 and the movable-side connector 43 when the fixed-side connector 41 is fixed to the first fixed platen 11A and the second fixed platen 11B, and the movable-side connector 43 is fixed to the first movable platen 13A and the second movable platen 13B. That is, as shown in Figures 14(a) and (b), it is preferable that the edges E on both sides in the width direction W of the fixed-side connector 41 and the movable-side connector 43 cross the center line CV extending in the vertical direction V between the first fixed platen 11A and the second movable platen 13B. Here, the centers of gravity of the first fixed platen 11A to the second movable platen 13B are on the center line CV, and the first fixed platen 11A to the second movable platen 13B are easily rotated around the center line CV. For example, as shown in Figure 14(c), if one edge E in the width direction W does not cross the center line CV, the second fixed platen 13A and the second movable platen 13B are easily rotated around the center line CV. However, as shown in Figures 14(a) and (b), if both edges E in the width direction W of the fixed-side connector 41 and the movable-side connector 43 are in the hatched area that crosses the center line CV, the position of the centers of gravity of the first fixed platen 11A to the second movable platen 13B, which are likely to become the center of rotation, can be contained within the fixed area of ​​the fixed-side connector 41 and the movable-side connector 43. This makes it difficult for the first fixed platen 11A to the second movable platen 13B to rotate relative to the fixed connector 41 and the movable connector 43, and is effective in preventing the fixed connector 41 and the movable connector 43 from tilting relative to the fixed connector 41 and the movable connector 43.

[0031] Furthermore, this allows the first movable platen 13A and the second movable platen 13B to be connected without tilting relative to each other. As a result, the direction of the clamping force between the first fixed platen 11A and the second fixed platen 11B, and between the first movable platen 13A and the second movable platen 13B, which are directly subjected to clamping force during mold clamping, becomes the same (parallel), preventing unexpected bending deformation from occurring in the fixed-side connector 41, the movable-side connector 43, the fixed mold 51, and the movable mold 53. In this case, it is even more preferable that the first fixed platen 11A and the second fixed platen 11B are fixed on the same surface of the fixed-side connector 41 so as to be in close contact over almost the entire surface of the first opposing surface 11C and the second opposing surface 11D.

[0032] Furthermore, it is preferable that the fixed-side connector 41 and the movable-side connector 43 are each a single plate-shaped member that covers the areas on the first opposing surface 11C and the second opposing surface 11D, and the third opposing surface 13C and the fourth opposing surface 13D where the molds are attached. This allows the mounting surface to be a flat surface without any steps, even if the mold is large enough that the mold end is close to the tie bar 17 when the mold is attached. This prevents localized dents (crushing) that would occur if steps were pressed against the mounting surface on the mold side.

[0033] [Second embodiment: See Figures 5 and 6] Next, the clamping device 10-2 according to the second embodiment will be described. The clamping device 10-2 includes a fixed-side intermediate body 45 between the fixed-side connector 41 and the first fixed platen 11A and the second fixed platen 11B, and a movable-side intermediate body 47 between the movable-side connector 43 and the first movable platen 13A and the second movable platen 13B. In other words, the fixed mold 51 is attached to the first fixed platen 11A and the second fixed platen 11B via the fixed-side connector 41 and the fixed-side intermediate body 45, and the movable mold 53 is attached to the first movable platen 13A and the second movable platen 13B via the movable-side connector 43 and the movable-side intermediate body 47.

[0034] The fixed intermediate body 45 and the movable intermediate body 47 are slidable relative to each other on the surfaces that contact the fixed connecting body 41 and the movable connecting body 43. Furthermore, the fixed intermediate body 45 and the movable intermediate body 47 are slidable relative to each other on the surfaces that contact the first fixed platen 11A and the second fixed platen 11B, and the first movable platen 13A and the second movable platen 13B.

[0035] To achieve the above functions, the fixed intermediate body 45 and the movable intermediate body 47 are preferably made of high-carbon steel such as carbon tool steel or alloy tool steel, which has high hardness and is easy to process to create a smooth surface. Furthermore, it is preferable to apply a highly slidable surface treatment such as chromium plating or vapor deposition.

[0036] Because the fixed-side intermediate body 45 and the movable-side intermediate body 47 have the sliding properties described above, as shown in Figure 6, tensile stress σi is generated in the first fixed platen 11A and the second fixed platen 11B and the first movable platen 13A and the second movable platen 13B, causing the first fixed platen 11A and the second fixed platen 11B and the first movable platen 13A and the second movable platen 13B to be pulled in a direction that separates them. Even so, slippage occurs at the surfaces where the fixed-side intermediate body 45 and the movable-side intermediate body 47 are in contact with the fixed-side connector 41 and the movable-side connector 43. Furthermore, slippage occurs at the surfaces where the fixed-side intermediate body 45 and the movable-side intermediate body 47 are in contact with the first fixed platen 11A and the second fixed platen 11B and the first movable platen 13A and the second movable platen 13B. These sliding movements release some or all of the tensile stress σi, preventing the first fixed platen 11A and the second fixed platen 11B, as well as the first movable platen 13A and the second movable platen 13B, from transmitting the stretching force associated with the tensile stress σi to the mold 50 via the mold connector 40.

[0037] Furthermore, the fixed-side intermediate body 45 may be more easily deformable between the fixed-side connector 41 and the first fixed platen 11A and the second fixed platen 11B than between the fixed-side connector 41 and the first fixed platen 11A and the second fixed platen 11B. Also, the movable-side intermediate body 47 may be more easily deformable between the movable-side connector 43 and the first movable platen 13A and the second movable platen 13B than between the movable-side connector 43 and the first movable platen 13A and the second movable platen 13B.

[0038] According to this, it is preferable that the fixed-side intermediate body 45 is made of a material or elastic body with lower rigidity than the fixed-side connecting body 41 and either the first fixed platen 11A or the second fixed platen 11B, and it is preferable that the movable-side intermediate body 47 is made of a material or elastic body with lower rigidity than the movable-side connecting body 43 and either the first movable platen 13A or the second movable platen 13B. As a material with low rigidity, for example, a low-hardness metal material such as aluminum or copper with an elastic modulus lower than that of cast iron or carbon steel may be used, and as an elastic body, rubber or spring material may be used.

[0039] If the fixed-side intermediate body 45 has the above-mentioned deformability, the difference in the amount of deformation between the fixed-side connector 41 and the first fixed platen 11A and the second fixed platen 11B can be absorbed by the deformation of the fixed-side intermediate body 45. Also, if the fixed-side intermediate body 47 has the above-mentioned deformability, the difference in the amount of deformation between the movable-side connector 43 and the first movable platen 13A and the second movable platen 13B can be absorbed by the deformation of the movable-side intermediate body 47. These deformations release some or all of the tensile stress σi, preventing the stretching force associated with the tensile stress σi of the first fixed platen 11A and the second fixed platen 11B and the first movable platen 13A and the second movable platen 13B from being transmitted to the mold 50 via the mold connector 40.

[0040] [Third and fourth embodiments: Figures 7 and 8] In this embodiment, other elements can be added to the clamping device 10-1, or some elements can be replaced with other elements. As an example, the third embodiment (clamping device 10-3, Figure 7) and the fourth embodiment (clamping device 10-4, Figure 8) will be described. Here, we will describe clamping devices 10-3 and 10-4 which utilize clamping device 10-1, but clamping device 10-2 can also be used.

[0041] [Clamping device 10-3: See Figure 7] The clamping device 10-3 includes tie bar support plates 21A and 21B that support the tie bars 17, located behind (R) the first movable platen 13A and the second movable platen 13B, and spaced apart from the first movable platen 13A and the second movable platen 13B. The tie bar support plates 21A and 21B are mounted on a base on which the first fixed platen 11A and the second fixed platen 11B are placed, and are movable back and forth.

[0042] The tie bar support plate 21A is provided in conjunction with the first movable plate 13A and supports four tie bars 17 that pass through the first movable plate 13A. A fixing nut 22 is fitted to each tie bar 17 that passes through the tie bar support plate 21A, connecting and fixing the tie bar support plate 21A and the tie bar 17 to prevent the tie bars 17 from sagging under their own weight. The tie bar support plate 21B is provided in conjunction with the second movable plate 13B and supports four tie bars 17 that pass through the second movable plate 13B. A fixing nut 22 is fitted to each tie bar 17 that passes through the tie bar support plate 21B, connecting and fixing the tie bar support plate 21B and the tie bars 17 to prevent the tie bars 17 from sagging under their own weight. Furthermore, since the main role of tie bar support plates 21A and 21B is to support the tie bar 17 so that it does not sag under its own weight, the tie bar support plates 21A and 21B do not need to be connected and fixed together. They can simply be fitted together with a length that prevents them from falling out when the ram 16 moves.

[0043] When the fixed mold 51 and the movable mold 53 are separated to perform the mold opening operation, the tie bars 17 are released from their restraint by the split nuts 19, and the first movable platen 13A and the second movable platen 13B are moved backward. At this time, the tie bar support plates 21A and 21B each support four tie bars 17. When the first movable platen 13A and the second movable platen 13B are advanced to perform the mold closing operation, the tie bar support plates 21A and 21B each support four tie bars 17.

[0044] [Clamping device 10-4: See Figure 8] Next, the clamping device 10-4 transmits the output of the drive source to the first movable platen 13A and the second movable platen 13B via the first toggle link mechanism 25A and the second toggle link mechanism 25B, causing the first movable platen 13A and the second movable platen 13B to move forward and backward. In other words, the clamping device 10-1 moves the first movable platen 13A and the second movable platen 13B forward and backward using the output of hydraulic cylinders provided on the first fixed platen 11A and the second fixed platen 11B, but the clamping device 10-4 does not have hydraulic cylinders on the first fixed platen 11A and the second fixed platen 11B. The clamping device 10-4 includes a first support platen 23A and a second support platen 23B for supporting the first toggle link mechanism 25A and the second toggle link mechanism 25B between the first movable platen 13A and the second movable platen 13B. The first support plate 23A and the second support plate 23B are fixed in relative positions to the first fixed plate 11A and the second fixed plate 11B, respectively, via tie bars 17. The drive source for extending and retracting the first toggle link mechanism 25A and the second toggle link mechanism 25B is arbitrary; for example, an electric motor can be used, and a mechanism that converts the rotational motion of the electric motor into linear motion can be interposed. Alternatively, instead of using linear motion driven by an electric motor, the first toggle link mechanism 25A and the second toggle link mechanism 25B may be driven by the extension motion of a hydraulic actuator.

[0045] The first toggle link mechanism 25A corresponds to the first clamping device 10A and is provided between the first movable platen 13A and the first support platen 23A. The second toggle link mechanism 25B corresponds to the second clamping device 10B and is provided between the second movable platen 13B and the second support platen 23B. As the first support platen 23A and the second support platen 23B are provided, four tie bars 17 pass through the first support platen 23A and the second support platen 23B, respectively. A fixing nut 22 is fitted to each tie bar 17 that passes through the first support platen 23A, connecting and fixing the first support platen 23A and the tie bars 17, respectively, and restraining the rearward (R) movement of the first support platen 23A. Furthermore, each of the four tie bars 17 that penetrate the second support plate 23B is fitted with a fixing nut 22, which connects and fixes the second support plate 23B and the tie bars 17, thereby restraining the rearward (R) movement of the second support plate 23B.

[0046] The clamping device 10-4 has four tie bars 17 that pass through the first fixed platen 11A and the second fixed platen 11B, and fixing nuts 27 are fitted onto the tie bars 17. Thus, the first fixed platen 11A and the second fixed platen 11B are constrained from moving forward (F). The relative positions of the first fixed platen 11A and the first support platen 23A, and the relative positions of the second fixed platen 11B and the second support platen 23B are fixed via the tie bars 17.

[0047] When clamping the fixed mold 51 and the movable mold 53, the first toggle link mechanism 25A and the second toggle link mechanism 25B are extended. Because the relative positions of the first fixed platen 11A and the second fixed platen 11B, and the first support platen 23A and the second support platen 23B are fixed, the fixed mold 51 and the movable mold 53 are pressed against each other.

[0048] In the example described above, movable side connectors 43 were also provided on the first movable platen 13A and the second movable platen 13B, but these can be omitted. Generally, in clamping devices 10-4 using a toggle link mechanism, the toggle link mechanism may be mounted closer to the center of the movable platen. In this case, the clamping force applied to the movable platen is applied to approximately the center in the width direction W, so the deflection in the clamping direction is reduced near the four corners of the movable platen, and the deflection at the ends of the platen in the width direction W caused by the deflection of the platen in the clamping direction is also reduced. Since the deflection at the ends of the platen in the width direction W is reduced, the tensile stress σi in the width direction W is also reduced, so even if the stress line Lσ flows into the inside of the mold, it may not cause any problems. This also applies to direct pressure type clamping mechanisms using hydraulic cylinders. As explained above, the fixed-side connector 41 is more essential than the movable-side connector 43.

[0049] The above describes examples of applications of the clamping device 10-1, but the clamping device 10-1 in the present invention can be further modified by adding other elements applicable to injection molding, or by replacing other elements.

[0050] [Fifth embodiment: See Figures 9 and 10] In the fifth embodiment of the mold clamping device 10-5, the shapes of the fixed-side connector 41 and the movable-side connector 43 have been modified. Specifically, as shown in Figure 9, at the ends of the fixed-side connector 41 in the width direction W and at the ends of the movable-side connector 43 in the width direction W, the surfaces that contact the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B, respectively, have been thinned 29 to reduce their thickness. As a result, in these portions, a larger gap is formed between the fixed-side connector 41 and the movable-side connector 43 and the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B at the edges than at the center of the mold.

[0051] When the fixed mold 51 and the movable mold 53 are clamped, the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B flex. However, at the ends of the fixed-side connector 41 and the movable-side connector 43 corresponding to the parts of the first movable platen 13A and the second movable platen 13B that flex the most, the surfaces that contact the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B are thinned 29, creating a gap between the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B and the fixed-side connector 41 and the movable-side connector 43. This gap absorbs the deflection at the ends of the first movable platen 13A and the second movable platen 13B, so the fixed-side connector 41 and the movable-side connector 43 are not subjected to load from the deflection of the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B, or if they are subjected to load, the load can be kept to a minimum. Therefore, the influence of platen deflection on the mold can be reduced.

[0052] Here, an example is shown in which the thinning 29 is provided on the fixed-side connector 41 and the movable-side connector 43. However, similar effects can be obtained by providing the thinning 29 in the corresponding parts of the first fixed platen 11A, the second fixed platen 11B, the first movable platen 13A, and the second movable platen 13B.

[0053] In addition to the above, it is possible to select or replace the configurations listed in the above embodiments, or to change them to other configurations as appropriate, as long as it does not deviate from the spirit of the present invention. Although the fixed-side connector 41 and the movable-side connector 43 have been exemplified above as preferred embodiments, the present invention is not limited to these, and embodiments as illustrated in Figure 13 can also be adopted. Note that Figure 13 shows the first fixed platen 11A and the second fixed platen 11B, but the following embodiments can also be adopted for the first movable platen 13 and the second movable platen 13B.

[0054] Figure 13(a) shows an example in which a fixed-side connector 41A is provided in a limited area spanning the first fixed platen 11A and the second fixed platen 11B to connect the first fixed platen 11A and the second fixed platen 11B. In this case, dummy parts 42, 42 are provided on both sides of the fixed-side connector 41A to form a flush surface for attaching the fixed mold 51. Figure 13(b) shows an example in which a fixed-side connecting body 41B is provided on the back surface of the surface to which the fixed mold 51 is attached, thereby connecting the first fixed platen 11A and the second fixed platen 11B. Figure 13(c) shows an example in which a fixed-side connecting body 41C is provided between the first fixed platen 11A and the second fixed platen 11B to connect the first fixed platen 11A and the second fixed platen 11B. Figure 13(d) shows an example in which a fixed-side connecting body 41C is provided on the upper surfaces of the first fixed platen 11A and the second fixed platen 11B to connect the first fixed platen 11A and the second fixed platen 11B. As described above, the connecting body in the present invention includes connecting any part between two individually manufactured fixed plates, or connecting any part between two individually manufactured movable plates. [Explanation of Symbols]

[0055] 1,100 Injection molding machine 10,10-1,10-2,10-3,10-4,10-5 Mold clamping device 10A 1st mold clamping device 10B 2nd mold clamping device 11A 1st fixed plate 11B 2nd fixed plate 11C 1st facing surface 11D Second opposing surface 13A 1st movable plate 13B 2nd movable board 13C Third opposing surface 13D Fourth opposing surface 16 Lamb 17 Tie Bar 19 Split nuts 18-type clamping hydraulic chamber 18A Type Clamping Chamber Type 18B Open-side chamber 21A,21B Tie bar support board 22,27 Fixing nuts 30 Injection device 31. Injection barrel 40 Mold connection body 41 Fixed side connection body 43 Movable side connection body 45 Fixed-side intermediate 47 Movable Intermediate Body 50 molds 51 Fixed mold 53. Movable mold

Claims

1. First fixed panel and second fixed panel, A first movable plate corresponding to the first fixed platen and a second movable plate corresponding to the second fixed platen, A fixed-side connecting member connecting the first fixed plate and the second fixed plate, The system comprises one or both of the movable side connecting members that connect the first movable platen and the second movable platen, If either the fixed-side connector or the movable-side connector is provided, the fixed-side connector is capable of mounting a fixed mold, or the movable-side connector is capable of mounting a movable mold. A clamping device comprising both the fixed-side connector and the movable-side connector, wherein the fixed-side connector is capable of mounting a fixed mold, and the movable-side connector is capable of mounting a movable mold.

2. The first fixed platen is provided with a first opposing surface, and the second fixed platen is provided with a second opposing surface. The first movable platen has a third opposing surface which is opposite to the first opposing surface, and the second movable platen has a fourth opposing surface which is opposite to the second opposing surface. The fixed-side connecting body spans the first opposing surface and the second opposing surface and connects the first fixed platen and the second fixed platen, and The movable side connecting body, which spans the third and fourth opposing surfaces and connects the first and second movable plates, comprises one or both of the following: The clamping device according to claim 1.

3. The fixed-side connector is The first and second mounting plates are fixed in a manner that allows for easy attachment and detachment. The movable side connector is The first movable plate and the second movable plate are fixed in a manner that allows for easy attachment and detachment. A clamping device according to claim 1 or claim 2.

4. The fixed-side connecting body and the fixed-side intermediate body provided between the first fixed platen and the second fixed platen, The system comprises the movable side connecting body and a movable side intermediate body provided between the first movable platen and the second movable platen, A clamping device according to claim 1 or claim 2.

5. The aforementioned fixed-side intermediate body is The fixed-side connecting body is slidable relative to the first fixed platen and the second fixed platen, or The fixed-side connecting body has lower rigidity than the first fixed plate and the second fixed plate. The movable intermediate body is The movable side connector is slidable relative to the first movable platen and the second movable platen, or The movable side connector has lower rigidity than the first movable platen and the second movable platen. The clamping device according to claim 4.

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