Hydraulic pre-pressing mechanism and hydraulic tool

Abstract

The utility model discloses a hydraulic pre-pressing mechanism and a hydraulic tool comprising the hydraulic pre-pressing mechanism. The hydraulic pre-pressing mechanism comprises a pre-pressing oil cylinder, the pre-pressing oil cylinder is a double-acting rotary pressing oil cylinder and comprises a cylinder body, a cylinder cover fixed to the front end of the cylinder body and a cylinder rod penetrating through the cylinder cover and extending out of the cylinder body, and the cylinder rod is provided with a first angular position in a release state and a second angular position in a pressing state; the pressing arm is fixedly installed at the outer end of the cylinder rod, a buffering cushion is installed on the inner side of the tail end of the pressing arm, the pressing arm is provided with a body part and an arm part which is staggered by a certain distance relative to the body part in the extending direction of the cylinder rod, and the buffering cushion is fixed in a groove formed in the tail end of the arm part. Automatic pre-pressing and releasing of the pre-pressing mechanism are achieved.

Description

Technical Field

[0001] The present application relates to a hydraulic pre-pressing mechanism for a machine tool and a hydraulic tool comprising the hydraulic pre-pressing mechanism. Background Art

[0002] Hydraulic fixture is a device driven by hydraulic pressure, which is used to position and clamp workpieces for machining on machine tools. There are positioning elements on the hydraulic fixture. In order to ensure that the workpiece and the positioning element are firmly attached, a pre-pressing mechanism is required to press the workpiece onto the positioning element. However, in many cases, the position of the pre-pressing mechanism is the machining surface of the workpiece. After the fixture is clamped, the pre-pressing mechanism needs to be moved or rotated to other positions, otherwise machining interference will occur.

[0003] In the case where the machine tool can only provide a single oil supply channel for the hydraulic tooling, the current hydraulic pre-clamping mechanism cannot automatically move or rotate from the clamping position to other positions. Therefore, the pre-clamping mechanism can only be used manually, and its operation steps are: manually operate the pre-clamping mechanism to pre-clamp the workpiece; start the oil supply channel of the machine tool to supply oil to the hydraulic tooling to complete the tooling clamping; after clamping is completed, manually remove the pre-clamping mechanism to prevent processing interference. This pre-clamping mechanism requires manual operation, with a low degree of automation and a long time. If the operator does not use the pre-clamping mechanism, it may cause the tooling positioning to fail and produce scrap. If the operator forgets to take away the pre-clamping mechanism, there will be a serious risk of machine tool collision. Utility Model Content

[0004] The present application aims to provide a hydraulic tooling capable of realizing automatic pre-compression and release on a machine tool.

[0005] According to one aspect of the present application, a hydraulic pre-pressing mechanism is provided for pre-pressing a workpiece on a machine tool, the hydraulic pre-pressing mechanism comprising:

[0006] A pre-compression oil cylinder, which is a double-acting rotary downward-pressing oil cylinder, comprising a cylinder body, a cylinder cover fixed to the front end of the cylinder body, and a cylinder rod extending from the cylinder body through the cylinder cover, wherein the cylinder rod has a first angular position in a released state and a second angular position in a downward-pressing state; and

[0007] The pressure arm is fixedly installed on the outer end of the cylinder rod, and a buffer pad is installed on the inner side of the end of the pressure arm. The pressure arm has a main body and an arm portion that is offset a distance relative to the main body along the extension direction of the cylinder rod. The buffer pad is fixed in a groove formed at the end of the arm portion.

[0008] In one embodiment, a mounting hole is formed in the main body, and the outer end of the cylinder rod is inserted into the mounting hole. A pair of screw holes leading to the mounting hole are formed on the side of the main body, and a fixing screw is screwed into each screw hole to fix the outer end of the cylinder rod in the pressure arm.

[0009] In one embodiment, a guide groove is formed on the pressure arm, and a guide pin is installed on the cylinder cover. When the cylinder rod is in the second angular position, the guide pin is aligned with the guide groove and is used to be inserted into the guide groove to guide the pressure arm to be pressed downward during the pressure arm pressing process.

[0010] In one embodiment, the cylinder head has a rectangular parallelepiped shape; at a first angular position of the cylinder rod, the pressure arm is parallel to a pair of side edges of the cylinder head; at a second angular position of the cylinder rod, the pressure arm is parallel to another pair of side edges of the cylinder head.

[0011] The present application further provides a hydraulic tooling for clamping a workpiece on a machine tool, the hydraulic tooling comprising:

[0012] A control channel, comprising a first sequence valve and a second sequence valve located downstream of the first sequence valve, wherein the first sequence valve and the second sequence valve divide the control channel into an upstream section, a midstream section, and a downstream section;

[0013] The hydraulic pre-compression mechanism of the present application, wherein the rod chamber of the pre-compression oil cylinder of the hydraulic pre-compression mechanism is connected to the upstream section, and the rodless chamber is connected to the downstream section;

[0014] A tooling clamping cylinder is connected to the midstream section.

[0015] In one embodiment, the control oil pressure of the first sequence valve is taken from the upstream section, the control oil pressure of the second sequence valve is taken from the midstream section, and the control oil pressures of the first sequence valve and the second sequence valve are adjustable.

[0016] In one embodiment, the control channel is connected to the first control oil port, the rodless chamber of the tooling clamping cylinder is connected to the midstream section via the first tooling pipeline, and the rod chamber of the tooling clamping cylinder is connected to the second control oil port via the second tooling pipeline.

[0017] In one embodiment, a first one-way valve connected to the first sequence valve and a second one-way valve connected in parallel to the second sequence valve are further provided in the control channel.

[0018] In one embodiment, the tool clamping cylinder is connected to the midstream section via a reversing valve, and the reversing valve is configured to control the supply of hydraulic oil from the midstream section to the rod chamber or the rodless chamber of the tool clamping cylinder.

[0019] In one embodiment, there are multiple hydraulic pre-stressing mechanisms, and the rod chamber of the pre-stressing cylinder of each hydraulic pre-stressing mechanism is connected to the upstream section, and the rodless chamber is connected to the downstream section.

[0020] The hydraulic pre-tensioning mechanism according to the present application can realize automatic pre-tensioning and release of the pre-tensioning mechanism when the machine tool only provides a single oil supply channel for the hydraulic tooling. The operation steps of the hydraulic tooling are simplified as follows: start the oil supply channel of the machine tool to supply oil to the hydraulic tooling, and under the drive of the hydraulic oil, the tooling automatically completes a series of actions of pre-tensioning-tooling clamping-pre-tensioning release. Various problems existing in manual pre-tensioning mechanisms are avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The foregoing and other aspects of the present application will be more fully understood through the following detailed description made with reference to the accompanying drawings, in which:

[0022] Figure 1-Figure 3 They are respectively a stereoscopic view, a top view and a front view of a hydraulic pre-compression mechanism in a released state according to an embodiment of the present application;

[0023] Figure 4 , Figure 5 They are respectively a stereoscopic view and a front view of the hydraulic pre-compression mechanism in a downward pressing state;

[0024] Figure 6 , Figure 7 It is a view of the pressing arm in the hydraulic pre-pressing mechanism from different directions;

[0025] Figure 8 is a three-dimensional diagram of the hydraulic pre-compression mechanism of the present application in a released state;

[0026] Fig. 9 is a three-dimensional diagram of the hydraulic pre-compression mechanism of the present application in a pre-compression state;

[0027] Fig.10 It is a hydraulic diagram of an embodiment of a hydraulic tooling including the hydraulic pre-compression mechanism;

[0028] Fig.11 is a hydraulic diagram of another embodiment of a hydraulic tooling including the hydraulic pre-compression mechanism;

[0029] Fig.12 It is a hydraulic diagram of another embodiment of a hydraulic tooling including the hydraulic pre-tensioning mechanism. DETAILED DESCRIPTION

[0030] The present application generally relates to a hydraulic pre-clamping mechanism for a machine tool and a hydraulic tooling including the hydraulic pre-clamping mechanism. A single oil supply channel is provided in the machine tool for the hydraulic tooling, that is, there is only one hydraulic oil circuit in the machine tool to supply oil to the hydraulic tooling, and the hydraulic oil in the circuit is responsible for driving all clamping actions of the hydraulic tooling.

[0031] An exemplary structure of the hydraulic pre-compression mechanism (hereinafter referred to as the pre-compression mechanism) 1 of the present application is Figure 1-Figure 5 It is shown in Figure 1-Figure 3 The release state of the pre-tensioning mechanism 1 is shown from different angles. Figure 4 , Figure 5 The pre-stressing state of the pre-stressing mechanism 1 is shown from different angles.

[0032] As shown in the figure, the pre-stressing mechanism 1 includes a pre-stressing oil cylinder 2, which is a double-acting rotary downward pressure oil cylinder available on the market, or is specially customized according to application requirements (such as installation requirements). The pre-stressing oil cylinder 2 includes a cylinder body 3, a cylinder head 4 fixed to the front end of the cylinder body 3 and equipped with a pair of oil ports 5, and a cylinder rod 6 extending from the cylinder body 3 through the cylinder head 4. One of the pair of oil ports 5 is an oil port connected to the rod cavity of the cylinder body 3 (which can be called A port), and the other is an oil port connected to the rodless cavity of the cylinder body 3 (which can be called B port).

[0033] The pressure arm 7 is fixedly mounted on the outer end of the cylinder rod 6. The pressure arm 7 extends approximately perpendicular to the cylinder rod 6. A buffer pad 8 is mounted on one end of the pressure arm 7 by means such as screws. The buffer pad 8 can be made of elastic materials such as rubber, facing the side (inside) where the pre-stressing cylinder 2 is located. In the downward pressing state (actuated state) of the pre-stressing cylinder 2, the buffer pad 8 is pressed against the workpiece to be processed on the machine tool. The cylinder head 4 has a roughly rectangular shape, which is conducive to the positioning of the pre-stressing cylinder 2 on the workbench and the positioning of the pressure arm 7 relative to the cylinder head 4.

[0034] Under normal conditions, the cylinder rod 6 (and the pressure arm 7) are in a first angular position and a first extended length. When the axial thrust generated by the oil pressure in the rod chamber on the cylinder piston is greater than the axial thrust generated by the oil pressure in the rodless chamber on the cylinder piston, the pre-stressing cylinder 2 performs the two-stage downward pressing action described below. The first stage is a rotational retraction stage, in which the cylinder rod 6 swings around its central axis by a preset swing angle (for example, 90°) to reach a second angular position, and the cylinder rod 6 axially retracts a first axial stroke. Afterwards, in the second stage, the cylinder rod 6 axially retracts a second axial stroke (pure retraction, no rotation). The first axial stroke and the second axial stroke are the rated total stroke of the cylinder rod 6, that is, the total telescopic distance of the lever 6.

[0035] When the axial thrust generated by the oil pressure in the rodless chamber on the cylinder piston is greater than the axial thrust generated by the oil pressure in the rod chamber on the cylinder piston, the pre-compression cylinder 2 performs a releasing action opposite to the pressing action.

[0036] In the release state (non-actuated state) of the pre-load cylinder 2, see Figure 1-Figure 3 The cylinder rod 6 extends a distance from the cylinder body 3, and the pressure arm 7 extends along a first direction. The first direction is perpendicular to the central axis of the cylinder rod 6 and is preferably parallel to a pair of side edges of the cylinder cover 4.

[0037] In the downward pressure state of the pre-load cylinder 2, see Figure 4 , Figure 5 , the cylinder rod 6 is retracted into the cylinder body 3 by the retracted distance, and the pressure arm 7 extends along the second direction. The second direction is perpendicular to the central axis of the cylinder rod 6 and forms the swing angle with the first direction, so as to be parallel to the other pair of side edges of the cylinder cover 4.

[0038] See also Figure 6 , Figure 7 The pressure arm 7 is roughly in the shape of a long strip and can be made of metal or hard plastic. The pressure arm 7 has a main body 7a and an arm 7b that is offset by a small distance relative to the main body 7a along the extension direction of the cylinder rod 6. The main body 7a forms a long hole-shaped mounting hole 7c from its rear surface to the front, and the outer end of the cylinder rod 6 is suitable for inserting into the mounting hole 7c. A pair of screw holes 7d leading to the mounting hole 7c are formed on the side of the main body 7a for screwing in a pair of fixing screws 9 (see the figure) to fix the outer end of the cylinder rod 6 in the pressure arm 7.

[0039] The buffer pad 8 is fixed in the groove formed at the end of the arm 7b so that a part of the buffer pad 8 protrudes from the rear surface of the arm 7b. When the pre-pressing cylinder 2 is pressed against the workpiece to compress the buffer pad 8, the buffer pad 8 is ensured to protrude from the rear surface of the arm 7b to a certain height to prevent the arm 7b from directly contacting the workpiece.

[0040] A guide groove 7e is formed on the side of the pressing arm 7 along the positive direction of the rotation direction when pressing down, which is defined between a pair of protrusions and is used for guiding the cylinder rod 6 when it is purely retracted. Correspondingly, a guide pin 4a extending toward the pressing arm 7 is installed on the cylinder cover 4 (see FIG. Figure 2 The guide pin 4a is parallel to the cylinder rod 6, and the guide pin 4a is arranged so that when the cylinder rod 6 is at the second angular position, the guide pin 4a is directly opposite to the guide groove 7e along its axial direction. In the second stage of the downward pressing action of the pre-pressing oil cylinder 2, as the pressing arm 7 is pressed downward, the guide pin 4a is inserted into the guide groove 7e and thus guides the pressing arm 7 to be pressed downward (see FIG. Figure 5 ), so that the buffer pad 8 is accurately pressed on the predetermined position of the workpiece.

[0041] The pre-tensioning mechanism 1 designed in this way can be used in a machine tool to pre-tension a workpiece. Specifically, the pre-tensioning mechanism 1 is equipped on a workbench of the machine tool. The pre-tensioning cylinder 2 is preferably installed in the workbench with its cylinder head 4. The pre-tensioning cylinder 2 is in a released state under normal conditions, and its pressing arm 7 is located at a position not facing the workpiece on the workbench. When the pre-tensioning cylinder 2 is actuated, the cylinder rod 6 drives the pressing arm 7 to first rotate and retract to a position where the buffer pad 8 faces a predetermined position on the workpiece, and then the cylinder rod 6 is further retracted so that the pressing arm 7 is pressed down on the workpiece with its buffer pad 8. In actual use, the actual total retraction distance of the cylinder rod 6 may be less than the rated total stroke of the cylinder rod 6.

[0042] Figure 8 , Fig. 9 Two states of the pre-compression mechanism of the present application are shown in a three-dimensional diagram.

[0043] Figure 8 , Fig. 9 The machine tool workbench 10 shown in the figure can process two workpieces 20 at the same time. A pre-pressing mechanism is provided for each workpiece. Each pre-pressing mechanism is installed in the workbench 10 through the cylinder cover of its pre-pressing cylinder.

[0044] exist Figure 8 In the released state of the pre-pressing mechanism shown, the pressing arm 7 of the pre-pressing mechanism is located below the workpiece 20 and in a substantially horizontal position, so as not to interfere with the entry and exit of the workpiece 20 and the action of the clamping cylinder (not shown) of the hydraulic tooling.

[0045] exist Fig. 9 In the downward pressing state of the pre-pressing mechanism shown in the figure, the pressing arm 7 of the pre-pressing mechanism is located at the workpiece 20 and rotated to a substantially vertical position, so that the buffer pad 8 faces the workpiece 20, and the pressing arm 7 is pressed downward so that the buffer pad 8 is pressed against the workpiece 20. After the clamping cylinder (not shown) of the hydraulic tooling clamps the workpiece 20, the pre-pressing mechanism returns to the original position. Figure 8 The released state shown does not interfere with the machining of the workpiece 20 by the machine tool.

[0046] Some feasible implementations of the hydraulic tooling using the above-mentioned pre-pressing mechanism 1 are introduced below.

[0047] See also Fig.10 In a hydraulic tooling of the present application, a first control oil port PA and a second control oil port PB are included. By switching the valve position of a reversing valve (not shown), the first control oil port PA can be connected to a single oil supply channel provided for the hydraulic tooling in the machine tool or to an oil tank, and the second control oil port PB can be connected to the oil supply channel or to an oil tank through a pressure reducing valve.

[0048] The hydraulic tooling includes a control channel L1 starting from the first control oil port PA. A first sequence valve V1 and a second sequence valve V2 located downstream of the first sequence valve V1 are arranged in the control channel L1. The first sequence valve V1 and the second sequence valve V2 divide the control channel L1 into an upstream section L1a, a midstream section L1b, and a downstream section L1c. The control oil pressure of the first sequence valve V1 is taken from the upstream section L1a, and the control oil pressure of the second sequence valve V2 is taken from the midstream section L1b. A pre-tensioning mechanism 1 and a tooling clamping cylinder 11 are used in the hydraulic tooling. The control oil pressure of the first sequence valve V1 and the second sequence valve V2 are adjustable.

[0049] The rod chamber of the pre-compression mechanism 1 is connected to the upstream section L1a through the pre-compression pipeline L2, and the rodless chamber of the pre-compression mechanism 1 is connected to the downstream section L1c.

[0050] The rodless chamber of the tool clamping oil cylinder 11 is connected to the midstream section L1b through the first tool pipeline L3, and the rod chamber of the tool clamping oil cylinder 11 is connected to the second control oil port PB through the second tool pipeline L4.

[0051] After the workpiece is loaded onto the workbench, when the hydraulic tooling operation is started, the first control oil port PA is connected to the machine tool oil supply channel through the reversing valve, and the second control oil port PB is connected to the oil tank. After the control oil pressure from the machine tool oil supply channel is supplied to the control channel L1 through the first control oil port PA, the oil pressure in the upstream section L1a increases, causing the oil pressure in the rod chamber of the pre-stressing oil cylinder 2 to increase, thereby the pre-stressing oil cylinder 2 performs a downward pressing action, that is, rotates and descends. The hydraulic oil in the rodless chamber of the pre-stressing oil cylinder 2 flows into the rodless chamber of the tooling clamping oil cylinder 11 through the downstream section L1c, the second one-way valve V2a, the midstream section L1b, and the first tooling pipeline L3, but the amount of this part of hydraulic oil is very small, which can only make the lever of the tooling clamping oil cylinder 11 extend a short distance.

[0052] After the pressing arm 7 is pressed against the workpiece, the pressing arm 7 stops moving, the oil pressure in the rod chamber of the pre-pressing cylinder 2 continues to increase, and the oil pressure in the upstream section L1a also increases, until the oil pressure in the upstream section L1a reaches the opening pressure of the first sequence valve V1, causing the first sequence valve V1 to open, and the hydraulic oil enters the midstream section L1b, and is supplied to the rodless chamber of the tooling clamping cylinder 11 through the first tooling pipeline L3, the hydraulic oil in the rod chamber of the tooling clamping cylinder 11 flows to the oil tank through the second tooling pipeline L4, and the lever of the tooling clamping cylinder 11 extends to clamp the workpiece.

[0053] After the tool clamping cylinder 11 clamps the workpiece, the oil pressure in the midstream section L1b continues to increase until it reaches the opening pressure of the second sequence valve V2, causing the second sequence valve V2 to open and the hydraulic oil to enter the downstream section L1c. The hydraulic oil enters the rodless chamber of the pre-stressing cylinder 2 from the downstream section L1c. At this time, the pressure in the rod chamber and the rodless chamber of the pre-stressing cylinder 2 is basically equal, but because the oil pressure action area of ​​the rodless chamber is larger than the oil pressure action area of ​​the rod chamber, the pre-stressing cylinder 2 begins to perform the release action, that is, reverse upward rotation until it reaches a fully released state. The tool clamping cylinder 11 keeps the workpiece clamped until the machine tool completes the processing of the workpiece. Afterwards, by switching the valve position of the control valve, the first control oil port PA is connected to the oil tank, and the second control oil port PB is connected to the oil supply channel of the machine tool. The control oil pressure from the oil supply channel is reduced in pressure by the pressure reducing valve and supplied to the second tooling pipeline L4 through the second control oil port PB, and enters the rod chamber of the tooling clamping cylinder 11. The hydraulic oil in the rodless chamber of the tooling clamping cylinder 11 returns to the oil tank through the first tooling pipeline L3, the midstream section L1b, the first one-way valve V1a, and the upstream section L1a, so that the lever of the tooling clamping cylinder 11 is retracted, and the tooling clamping cylinder 11 is released and leaves the workpiece.

[0054] according to Fig.10 The hydraulic tooling shown, when the machine tool only provides a single control channel for the hydraulic tooling, automatically realizes a series of actions of pre-compression of the workpiece - tooling clamping - pre-compression release through the linkage of the pre-compression cylinder 2 and the tooling clamping cylinder 11. The hydraulic tooling of the present application is easy to operate, does not require manual operation of the pre-compression mechanism, and can save operation time. Compared with the manual pre-compression mechanism, the automatic pre-compression mechanism has high pressure and reliable clamping. After the tooling clamping is completed, there is no need to manually remove the pre-compression mechanism, which fundamentally avoids the risk of machine tool collision.

[0055] See also Fig.11 In another hydraulic tooling of the present application, a first control oil port PA is included, which can be selectively connected to the machine tool oil supply channel or oil tank.

[0056] A first sequence valve V1 and a second sequence valve V2 located downstream of the first sequence valve V1 are provided in the control oil circuit L1. The first sequence valve V1 and the second sequence valve V2 divide the control oil circuit L1 into an upstream section L1a, a midstream section L1b, and a downstream section L1c. The control oil pressure of the first sequence valve V1 is taken from the upstream section L1a, and the control oil pressure of the second sequence valve V2 is taken from the midstream section L1b. A pre-clamping mechanism 1 and a tool clamping cylinder 11 are used in the hydraulic tooling. The control oil pressure of the first sequence valve V1 and the second sequence valve V2 is adjustable.

[0057] The rod chamber of the pre-compression mechanism 1 is connected to the upstream section L1a through the pre-compression pipeline L2, and the rodless chamber of the pre-compression mechanism 1 is connected to the downstream section L1c.

[0058] The tool clamping cylinder 11 is connected to the midstream section L1b via the reversing valve V3. The state of the tool clamping cylinder 11 is switched by the reversing valve V3. Specifically, in the first valve position of the reversing valve V3, the rodless chamber of the tool clamping cylinder 11 is connected to the midstream section L1b via the tool pipeline L3, and the rod chamber of the tool clamping cylinder 11 is connected to the oil tank. In the second valve position of the reversing valve V3, the rod chamber of the tool clamping cylinder 11 is connected to the midstream section L1b via the tool pipeline L3, and the rodless chamber of the tool clamping cylinder 11 is connected to the oil tank.

[0059] The first sequence valve V1 is connected in parallel with a first check valve V1a. One end of the first check valve V1a is connected to the upstream section L1a, and the other end is connected to the midstream section L1b, allowing the hydraulic oil in the midstream section L1b to flow to the upstream section L1a through the first check valve V1a, but prohibiting reverse flow.

[0060] The second sequence valve V2 is connected in parallel with a second check valve V2a. One end of the second check valve V2a is connected to the midstream section L1b, and the other end is connected to the downstream section L1c, allowing the hydraulic oil in the downstream section L1c to flow to the midstream section L1b through the second check valve V2a, but prohibiting reverse flow.

[0061] Fig.11 The operation of the hydraulic tool shown is as follows.

[0062] In the standby state of the hydraulic tooling, the pre-tensioning mechanism 1 is in a released state, the tooling clamping cylinder 11 is in a retracted state, the reversing valve V3 is in the first valve position, and the first sequence valve V1 and the second sequence valve V2 are both disconnected.

[0063] After the workpiece is loaded onto the workbench, when the hydraulic tooling operation is started, hydraulic oil is supplied to the control oil circuit L1 through the first control oil port PA, and the oil pressure in the upstream section L1a increases, causing the oil pressure in the rod chamber of the pre-pressing cylinder 2 to increase, thereby the pre-pressing cylinder 2 performs a downward pressing action, that is, rotates and descends. After the pressing arm 7 is pressed against the workpiece, the pressing arm 7 stops moving, the oil pressure in the rod chamber of the pre-pressing cylinder 2 continues to increase, and the oil pressure in the upstream section L1a also increases until the oil pressure in the upstream section L1a reaches the opening pressure of the first sequence valve V1, causing the first sequence valve V1 to open, and the hydraulic oil enters the midstream section L1b, and is supplied to the tooling clamping cylinder 11 through the reversing valve V3 in the first valve position. The tooling clamping cylinder 11 is actuated to clamp the workpiece. After the tool clamping cylinder 11 clamps the workpiece, the oil pressure in the midstream section L1b continues to rise until it reaches the opening pressure of the second sequence valve V2, causing the second sequence valve V2 to open and the hydraulic oil to enter the downstream section L1c. The hydraulic oil enters the rodless chamber of the pre-stressing cylinder 2 from the downstream section L1c. At this time, the pressure in the rod chamber and the rodless chamber of the pre-stressing cylinder 2 is basically equal, but because the oil pressure action area of ​​the rodless chamber is larger than the oil pressure action area of ​​the rod chamber, the pre-stressing cylinder 2 begins to perform the release action, that is, reverse upward rotation until it reaches a fully released state. The tool clamping cylinder 11 keeps the workpiece clamped until the machine tool completes the processing of the workpiece. Afterwards, the control valve V3 is switched to the second valve position, so that the tool clamping cylinder 11 is released and leaves the workpiece.

[0064] Fig.11 The hydraulic tooling shown can achieve Fig.10 The similar technical effects of the hydraulic tooling shown will not be repeated here.

[0065] For some machine tool applications, a larger workpiece may require more than one pre-load cylinder 2 and tool clamping cylinder 11. Alternatively, more than one workstation may be set up on the machine tool, and each workstation may process a workpiece. In this case, the hydraulic tool can be equipped with multiple pre-load cylinders 2 and tool clamping cylinders 11. For example, Fig.10 The hydraulic tooling shown in the figure adds a pre-compression cylinder 2 and a tooling clamping cylinder 11 to form Fig.12The structure shown in the figure (two pre-tensioning cylinders 2 and two tool clamping cylinders 11 are shown as examples). Among them, the rod chamber of each pre-tensioning cylinder 2 is respectively connected to the upstream section L1a of the control channel L1, and the rodless chamber is respectively connected to the downstream section L1c of the control channel L1. Each tool clamping cylinder 11 is respectively connected to the midstream section L1b of the control channel L1 via a corresponding control valve V3. When the control channel L1 is supplied with hydraulic oil, each pre-tensioning cylinder 2 acts synchronously, and each tool clamping cylinder 11 can also act synchronously. Fig.12 Other aspects of the hydraulic tooling shown are similar to Fig.10 The hydraulic tooling shown is similar and can achieve the same technical effect, so it will not be repeated here.

[0066] Understandably, Fig.11 The hydraulic tooling shown can also be supplemented with a pre-tensioning cylinder 2 and a tooling clamping cylinder 11 .

[0067] With respect to the specific structure of the pre-tensioning mechanism and the hydraulic tooling described above and shown in the accompanying drawings, a skilled technician can design them for a specific machine tool form under the basic principles of the present application.

[0068] Although the present application is described herein with reference to specific embodiments, the scope of the present application is not limited to the details shown. Various modifications may be made to these details without departing from the basic principles of the present application.

Claims

1. A hydraulic pre-pressing mechanism, used for pre-pressing a workpiece on a machine tool, characterized in that: The hydraulic pre-compression mechanism comprises: A pre-pressing oil cylinder (2) is a double-acting rotary downward-pressing oil cylinder, comprising a cylinder body (3), a cylinder cover (4) fixed to the front end of the cylinder body (3), and a cylinder rod (6) extending from the cylinder body (3) through the cylinder cover (4), wherein the cylinder rod (6) has a first angular position in a released state and a second angular position in a downward-pressing state; and A pressure arm (7) is fixedly mounted on the outer end of the cylinder rod (6), and a buffer pad (8) is mounted on the inner side of the end of the pressure arm (7). The pressure arm (7) comprises a main body (7a) and an arm (7b) which is offset by a distance relative to the main body (7a) along the extension direction of the cylinder rod (6), and the buffer pad (8) is fixed in a groove formed at the end of the arm (7b).

2. The hydraulic pre-tensioning mechanism according to claim 1, characterized in that: The main body (7a) is formed with a mounting hole (7c), the outer end of the cylinder rod (6) is inserted into the mounting hole (7c), and the side of the main body (7a) is formed with a pair of screw holes (7d) leading to the mounting hole (7c), and a fixing screw (9) is screwed into each screw hole (7d) to fix the outer end of the cylinder rod (6) in the pressure arm (7).

3. The hydraulic pre-tensioning mechanism according to claim 1, characterized in that: A guide groove (7e) is formed on the pressing arm (7), and a guide pin (4a) is installed on the cylinder cover (4). When the cylinder rod (6) is in the second angular position, the guide pin (4a) is aligned with the guide groove (7e) and is used to be inserted into the guide groove (7e) during the pressing process of the pressing arm (7) to guide the pressing arm (7) to be pressed downward.

4. The hydraulic pre-tensioning mechanism according to any one of claims 1 to 3, characterized in that: The cylinder cover (4) has a rectangular parallelepiped shape; at a first angular position of the cylinder rod (6), the pressure arm (7) is parallel to a pair of side edges of the cylinder cover (4); at a second angular position of the cylinder rod (6), the pressure arm (7) is parallel to another pair of side edges of the cylinder cover (4).

5. A hydraulic tool used for clamping a workpiece on a machine tool, characterized in that: The hydraulic tooling comprises: A control channel (L1), comprising a first sequence valve (V1) and a second sequence valve (V2) located downstream of the first sequence valve (V1), wherein the first sequence valve (V1) and the second sequence valve (V2) divide the control channel (L1) into an upstream section (L1a), a midstream section (L1b), and a downstream section (L1c); The hydraulic pre-stressing mechanism according to any one of claims 1 to 4, wherein the rod chamber of the pre-stressing cylinder (2) of the hydraulic pre-stressing mechanism is connected to the upstream section (L1a), and the rodless chamber is connected to the downstream section (L1c); A tool clamping cylinder (11) is connected to the midstream section (L1b).

6. The hydraulic tooling according to claim 5, characterized in that: The control oil pressure of the first sequence valve (V1) is taken from the upstream section (L1a), and the control oil pressure of the second sequence valve (V2) is taken from the midstream section (L1b). The control oil pressures of the first sequence valve (V1) and the second sequence valve (V2) are adjustable.

7. The hydraulic tooling according to claim 5, characterized in that: The control channel (L1) is connected to the first control oil port (PA), the rodless chamber of the tooling clamping cylinder (11) is connected to the midstream section (L1b) via the first tooling pipeline (L3), and the rod chamber of the tooling clamping cylinder (11) is connected to the second control oil port (PB) via the second tooling pipeline (L4).

8. The hydraulic tooling according to claim 7, characterized in that: The control channel (L1) is also provided with a first one-way valve (V1a) connected to the first sequence valve (V1) and a second one-way valve (V2a) connected in parallel to the second sequence valve (V2).

9. The hydraulic tooling according to claim 5, characterized in that: The tool clamping cylinder (11) is connected to the midstream section (L1b) via a reversing valve (V3), and the reversing valve (V3) is configured to control the supply of hydraulic oil from the midstream section (L1b) to the rod chamber or the rodless chamber of the tool clamping cylinder (11).

10. The hydraulic tooling according to any one of claims 5 to 9, characterized in that: There are multiple hydraulic pre-pressing mechanisms, and the rod chamber of the pre-pressing cylinder (2) of each hydraulic pre-pressing mechanism is connected to the upstream section (L1a), and the rodless chamber is connected to the downstream section (L1c).

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