Center frame for crankshaft grinding

Abstract

The utility model provides a center frame for crankshaft grinding. The center frame comprises a base, a hydraulic system, a horizontal ejector rod unit and a vertical ejector rod unit. In the hydraulic system, a first hydraulic cylinder and a second hydraulic cylinder provide the same driving force for a horizontal ejector rod unit and a vertical ejector rod unit, and a pressure reducing valve and a pressure gauge respectively adjust and detect the pressure of a hydraulic loop. In the horizontal ejector rod unit, a first guide mechanism guides a horizontal ejector rod and comprises a first linear bearing and a first guide rod which are installed on the base, one side of a first bottom plate is connected with a first hydraulic cylinder and the first guide rod, and the other side of the first bottom plate is connected with the horizontal ejector rod. In the vertical ejector rod unit, a second guide mechanism guides a vertical ejector rod and comprises a second linear bearing and a second guide rod which are installed on the base, one side of a second bottom plate is connected with a second hydraulic cylinder and the second guide rod, and the other side of the second bottom plate is connected with the vertical ejector rod. The device is simple in structure, adopts independent ejector rod units in the horizontal direction and the vertical direction, and is low in design precision requirement and reliable to use.

Description

Technical Field

[0001] The utility model belongs to the field of grinding machine tools, and in particular relates to a center frame for crankshaft grinding. Background Art

[0002] When grinding crankshafts or eccentric shafts, grinders generally use double-top grinding. Compared with ordinary shaft parts, crankshaft grinding has the following two problems: First, due to the large eccentricity of the crankshaft or eccentric shaft itself, when the workpiece rotates with the headstock, the centripetal force will cause the workpiece axis to swing; second, due to the special structure of the crankshaft, the crankshaft will bend and deform due to the grinding force and the clamping force during double-top grinding.

[0003] Due to the characteristics of crankshaft processing, a center stand is needed to help center the workpiece and unload the head and tail stands. At the same time, the tightening force of the center stand can be adjusted according to different grinding processes. The outer diameter gauge and center stand device must be arranged in the grinding position, so the space size of the center stand is required to be small.

[0004] Existing grinding center frames, such as the hydraulic center frame for grinding machines proposed in the Chinese patent application with announcement number CN217143569U, can meet the use requirements, but they need to achieve simultaneous and equal displacement movement in both horizontal and vertical directions, and have a complex structure with a chute plate and two wedges. These components and related components have high dimensional accuracy requirements, and a large number of detailed calculations are required during design to ensure accuracy. Therefore, they are expensive and have a long delivery time. In addition, when the above-mentioned center frame is in use, the wear between the high-precision components easily leads to gaps between the components and cannot ensure equal displacement in both directions, and the reliability is low. Utility Model Content

[0005] The utility model aims to solve the shortcomings of the prior art, namely, the complex structure, high design precision requirement and low reliability of the grinding center frame, and provides a center frame for crankshaft grinding, which has a simple structure, low design precision requirement and reliable use.

[0006] To achieve the above purpose, the technical solution provided by the utility model is:

[0007] A center stand for crankshaft grinding, which is special in that it comprises a base, a hydraulic system, a horizontal push rod unit and a vertical push rod unit;

[0008] The base is used to support the hydraulic system, the horizontal ram unit and the vertical ram unit;

[0009] The hydraulic system includes a first hydraulic cylinder, a second hydraulic cylinder, a pressure reducing valve and a pressure gauge.

[0010] The first hydraulic cylinder and the second hydraulic cylinder are fixed to the base, and are used to provide the same driving force for the horizontal ram unit and the vertical ram unit.

[0011] The pressure reducing valve and the pressure gauge are used to adjust and detect the pressure of the hydraulic circuit respectively, so as to adjust the pre-tightening force of the horizontal push rod unit and the vertical push rod unit on the workpiece;

[0012] The horizontal push rod unit includes a first guide mechanism, a first bottom plate and a horizontal push rod for contacting the side of the workpiece.

[0013] The first guide mechanism is used to guide the horizontal push rod, and includes a first linear bearing mounted to the base and a first guide rod passing therethrough, one side of the first base plate is connected to the first hydraulic cylinder and the first guide rod, and the other side is connected to the horizontal push rod;

[0014] The vertical ejector unit comprises a second guide mechanism, a second bottom plate and a vertical ejector for contacting the bottom of the workpiece.

[0015] The second guide mechanism is used to guide the vertical push rod, and includes a second linear bearing installed on the base and a second guide rod passing therethrough. One side of the second base plate is connected to the second hydraulic cylinder and the second guide rod, and the other side is connected to the vertical push rod.

[0016] Furthermore, the horizontal push rod unit also includes a horizontal contact, one end of which is mounted on the horizontal push rod and the other end is used to contact the workpiece; the vertical push rod unit also includes a vertical contact, one end of which is mounted on the vertical push rod and the other end is used to contact the workpiece.

[0017] Furthermore, the crankshaft grinding center frame also includes a detection unit, which includes a sensor. The sensor determines the position of the horizontal push rod through position detection.

[0018] Furthermore, the detection unit also includes a sensing bracket, which is connected to the first bottom plate, and the sensor is fixed to the base to determine the position of the horizontal push rod by detecting the position of the sensing bracket.

[0019] Furthermore, the detection unit also includes a sensor bracket, the sensor bracket is fixed to the base, and the sensor is mounted on the sensor bracket.

[0020] Furthermore, the first guide mechanism and the second guide mechanism also respectively include a first bearing mounting seat for accommodating the first linear bearing and a second bearing mounting seat for accommodating the second linear bearing, and both the first bearing mounting seat and the second bearing mounting seat are connected to the base.

[0021] Furthermore, the hydraulic system also includes an oil circuit blocking plate, which is mounted to the base. An oil circuit channel is opened in the oil circuit blocking plate and communicates with the oil circuit channel in the base so that the first hydraulic cylinder and the second hydraulic cylinder are connected in series.

[0022] The advantages of the utility model are:

[0023] The center stand for crankshaft grinding of the utility model comprises a horizontal push rod unit and a vertical push rod unit respectively arranged at the side and bottom of the workpiece to provide preload for the workpiece. The first hydraulic cylinder and the second hydraulic cylinder in the hydraulic system provide the same driving force for the two push rod units. The two push rod units each include a bottom plate, a push rod, and a guide mechanism to ensure the smooth movement of the push rod, namely a linear bearing and a guide rod. The size of the preload can be adjusted by a pressure reducing valve and a pressure gauge. Therefore, the utility model realizes the same adjustable preload at the side and bottom of the workpiece with a simple principle, has a simple structure, uses independent push rod units in the horizontal and vertical directions, does not require high-precision components such as wedges to ensure synchronous movement in the two directions, has low design precision requirements, and is reliable in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The features and advantages of the present invention will become more easily understood through the following description with reference to the accompanying drawings, which are not drawn to scale and some features are enlarged or reduced to show details of specific components.

[0025] In the figure:

[0026] Figure 1 It is a front view of the center stand for crankshaft grinding of the utility model;

[0027] Figure 2 It is a side view of a center stand for crankshaft grinding of the utility model.

[0028] In the figure:

[0029] 1- Base;

[0030] 11-first hydraulic cylinder, 12-second hydraulic cylinder, 13-oil path blocking plate, 14-oil inlet, 15-oil outlet;

[0031] 21-first linear bearing, 22-first guide rod, 23-first bottom plate, 24-horizontal push rod, 25-horizontal contact, 26-first bearing mounting seat, 27-horizontal contact screw, 28-bearing clamping screw;

[0032] 32-second guide rod, 33-second bottom plate, 34-vertical top rod, 35-vertical contact, 36-second bearing mounting seat, 37-vertical contact screw;

[0033] 41-sensor, 42-sensor bracket, 43-sensor bracket;

[0034] 100-working table, 200-retractor hook, 300-base screw;

[0035] 1000-artifacts. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below with reference to the accompanying drawings by means of exemplary embodiments of the present invention. It should be noted that the following detailed description of the present invention is only for the purpose of illustration, and is not intended to limit the present invention.

[0037] The utility model provides a center frame for crankshaft grinding, which is used for being fixed on a grinding machine workbench and provides an adjustable pre-tightening force to a crankshaft or eccentric shaft workpiece to be ground so as to assist the workpiece grinding.

[0038] Reference Figure 1 and Figure 2 As an exemplary embodiment of the present invention, a center stand for crankshaft grinding includes a base 1, a hydraulic system, a horizontal push rod unit and a vertical push rod unit.

[0039] The base 1 is used to support the hydraulic system, the horizontal push rod unit and the vertical push rod unit. The base 1 can be fixed on the workbench 100 of the grinding machine, in particular, it is connected to the workbench 100 through a hook 200 and a base screw 300, wherein the base screw 300 passes through the base 1 and is connected to the hook 200 installed on the workbench 100.

[0040] The hydraulic system includes a first hydraulic cylinder 11, a second hydraulic cylinder 12, and a pressure reducing valve and a pressure gauge which are not shown in the figure. The cylinder barrels of the first hydraulic cylinder 11 and the second hydraulic cylinder 12 are fixed to the base 1, optionally fixed by screw connection, and are used to provide the same driving force for the horizontal push rod unit and the vertical push rod unit, so that the horizontal push rod unit and the vertical push rod unit move the same distance, thereby ensuring that the side and bottom of the workpiece 1000 are supported by the same force, that is, providing the same preload force in both horizontal and vertical directions, which can effectively eliminate the influence of eccentricity and grinding force on processing. The first hydraulic cylinder 11 and the second hydraulic cylinder 12 can be connected in parallel or in series, as long as the forces provided by the two are the same. It should be understood that when connected in series, only one pressure reducing valve and pressure gauge need to be connected in series in the hydraulic circuit to control the preload force, and when connected in parallel, one pressure reducing valve and pressure gauge need to be connected in series in each of the two circuits. Preferably, an oil circuit plugging plate 13 may be provided for the hydraulic system, and the oil circuit plugging plate 13 is mounted to the base 1. An oil circuit passage is provided in the oil circuit plugging plate 13, which is in communication with the oil circuit passage in the base 1 (this can be achieved by known mature technology), so that the first hydraulic cylinder 11 and the second hydraulic cylinder 12 are connected in series. The oil inlet 14 and the oil outlet 15 of the hydraulic circuit may be arranged on the same side of the base 1 for easy operation. Those skilled in the art will understand that other structures, such as a one-inlet and two-outlet valve, may also be used to achieve the series connection of the first hydraulic cylinder 11 and the second hydraulic cylinder 12, but the use of the structure of the oil circuit plugging plate can avoid, for example, the space occupied by the valve in the center frame, effectively reduce the size of the center frame, and save the size space of the center frame.

[0041] The pressure reducing valve and the pressure gauge are used to adjust and detect the pressure of the hydraulic circuit respectively, so as to adjust the preload force of the horizontal push rod unit and the vertical push rod unit on the workpiece 1000. The pressure reducing valve and the pressure gauge can be connected to any position of the hydraulic circuit as long as it is convenient for the operator to operate.

[0042] The horizontal push rod unit includes a first guide mechanism, a first base plate, and a horizontal push rod 24 for contacting the side of the workpiece 1000. The first guide mechanism is used to guide the horizontal push rod 24, and includes a first linear bearing 21 mounted to the base 1 and a first guide rod 22 passing therethrough, the first guide rod 22 can slide smoothly along the first linear bearing 21, one side of the first base plate 23 is connected to the piston rod of the first hydraulic cylinder 11 and the first guide rod 22, and the other side is connected to one end of the horizontal push rod 24, so that when the first hydraulic cylinder 11 is actuated, its piston rod drives the first base plate 23 to move horizontally, and at the same time, the first guide rod 22 fixed to the base plate 23 translates along the first linear bearing 21 to guide the first base plate 23, so that the horizontal push rod 24 connected to the first base plate 23 moves horizontally with the first base plate 23 and is guided.

[0043] The vertical push rod unit includes a second guide mechanism, a second bottom plate 33 and a vertical push rod 34 for contacting the bottom of the workpiece 1000. The second guide mechanism is used to guide the vertical push rod 34, and includes a second linear bearing mounted to the base 1 (shielded by the second bearing mounting seat 36, not shown in the figure) and a second guide rod 32 passing therethrough, one side of the second bottom plate 33 is connected to the piston rod of the second hydraulic cylinder 12 and the second guide rod 32, and the other side is connected to one end of the vertical push rod 34. The working principle of the vertical push rod unit is similar to that of the horizontal push rod unit, which will not be repeated here.

[0044] In some embodiments, the first guide mechanism and the second guide mechanism further include a first bearing mounting seat 26 for accommodating the first linear bearing 21 and a second bearing mounting seat 36 for accommodating the second linear bearing, respectively. Both the first bearing mounting seat 26 and the second bearing mounting seat 36 are connected to the base 1, specifically, they can be connected by screws. The linear bearing is installed in this way instead of directly installing the linear bearing in the base 1, so that the structure of the base 1 is simpler and easier to process. The first linear bearing 21 can be pressed against the first bearing mounting seat 26 using a bearing clamping screw 28 to prevent the first linear bearing 21 from moving, and the same is true for the second linear bearing.

[0045] Since the tips of the horizontal push rod 24 and the vertical push rod 34 are in contact with the workpiece, the tips of the push rods will wear when the workpiece rotates, and the push rods will not be able to play a tightening role after a long time. Therefore, in some embodiments, the horizontal push rod 24 unit also includes a horizontal contact 25, one end of which is mounted on the horizontal push rod 24, especially connected to the horizontal push rod 24 through a horizontal contact screw 27, and the other end is used to contact the workpiece 1000. In addition, the vertical push rod 34 unit also includes a vertical contact 35, one end of which is mounted on the vertical push rod 34, especially connected to the vertical push rod 34 through a vertical contact screw 37, and the other end is used to contact the workpiece 1000. The cross-section of the contact can be rectangular or circular. The contact is made of wear-resistant material to delay the wear of the contact. When the contact is worn to the point that it cannot be used, a new contact can be replaced. In addition, the contact is preferably in point contact with the outer diameter of the workpiece, so as to avoid the push rod affecting the processing accuracy, so the tip of the contact is preferably in the form of a large arc.

[0046] In an exemplary embodiment of the present utility model, the crankshaft grinding center frame also includes a detection unit for detecting whether the push rod has hit the workpiece 1000. The detection unit includes a sensor 41. The sensor 41 determines the position of the horizontal push rod 24 by position detection to determine whether the horizontal push rod 24 has hit the workpiece. Since the driving force provided by the two groups of hydraulic cylinders is the same, it is only necessary to detect the position of one of the horizontal push rod 24 and the vertical push rod 34. The use of the sensor can more accurately determine whether the push rod has hit the workpiece, thereby improving the positioning accuracy of the center frame. The sensor 41 can be a proximity switch. The sensor 41 can be installed at any position of the center frame as long as the position of the horizontal push rod 24 can be detected.

[0047] The detection unit may further include a sensing bracket 42, the sensing bracket 42 is connected to the first bottom plate 23 to move with the first bottom plate 23, and the sensor 41 is fixedly connected to the base 1 to determine the position of the horizontal top rod 24 by detecting the position of the sensing bracket 42. The sensing bracket 42 may be formed by bending a thin plate, one end of which is fixedly connected to the first bottom plate 23 by screws, and the other end is located directly above the sensor 41.

[0048] Preferably, the detection unit further includes a sensor bracket 43 , the sensor bracket 43 is fixed to the base 1 , and the sensor 41 is mounted on the sensor bracket 43 .

[0049] Now the process of grinding a workpiece using the center stand for crankshaft grinding of the present invention is described:

[0050] Step 1, install the center frame on the grinding machine workbench and connect the hydraulic pipeline of the center frame;

[0051] Step 2: Install the qualified workpiece on the grinding machine, install two dial gauges at the position where the workpiece is tightened, confirm that the dial gauge has a range in both the + / - direction and set the pointer to zero;

[0052] Step 3, start the first hydraulic cylinder 11 and the second hydraulic cylinder 12, so that the horizontal push rod 24 and the vertical push rod 34 support the outer diameter of the workpiece;

[0053] Step 4, rotate the workpiece, adjust the pressure of the hydraulic circuit by adjusting the pressure reducing valve and observing the pressure gauge, and control the vibration of the dial gauge within the required range;

[0054] Step 5, remove the qualified workpiece and the dial indicator, install the blank and start grinding;

[0055] Step 6, check the machining accuracy of the blank. If the accuracy is qualified, it will be processed normally. If it is not qualified, repeat steps 2 to 4 and readjust the runout requirements of the micrometer until the machining accuracy of the workpiece is qualified.

[0056] As described above, the center stand for crankshaft grinding of the utility model comprises a horizontal push rod unit and a vertical push rod unit respectively provided at the side and bottom of the workpiece to provide preload for the workpiece, the first hydraulic cylinder and the second hydraulic cylinder in the hydraulic system provide the same driving force for the two push rod units, the two push rod units each include a bottom plate, a push rod and a guide mechanism to ensure the smooth movement of the push rod, i.e., a linear bearing and a guide rod, and the size of the preload can be adjusted by a pressure reducing valve and a pressure gauge. Therefore, the utility model realizes the same adjustable preload at the side and bottom of the workpiece with a simple principle, has a simple structure, uses independent push rod units in the horizontal and vertical directions, does not require high-precision components such as wedges to ensure synchronous movement in the two directions, has low design precision requirements, and is reliable to use.

[0057] The features mentioned and / or shown in the above description of the exemplary embodiments of the utility model can be combined in the same or similar manner into one or more other embodiments, combined with the features in other embodiments or replace the corresponding features in other implementations. The technical solutions obtained by these combinations or replacements should also be deemed to be included in the protection scope of the utility model.

Claims

1. A center stand for crankshaft grinding, characterized in that: It includes a base, a hydraulic system, a horizontal ram unit and a vertical ram unit; The base is used to support the hydraulic system, the horizontal ram unit and the vertical ram unit; The hydraulic system includes a first hydraulic cylinder, a second hydraulic cylinder, a pressure reducing valve and a pressure gauge. The first hydraulic cylinder and the second hydraulic cylinder are fixed to the base, and are used to provide the same driving force for the horizontal ram unit and the vertical ram unit. The pressure reducing valve and the pressure gauge are used to adjust and detect the pressure of the hydraulic circuit respectively, so as to adjust the pre-tightening force of the horizontal push rod unit and the vertical push rod unit on the workpiece; The horizontal push rod unit comprises a first guide mechanism, a first bottom plate and a horizontal push rod for contacting the side of the workpiece. The first guide mechanism is used to guide the horizontal push rod, and includes a first linear bearing mounted to the base and a first guide rod passing therethrough, one side of the first base plate is connected to the first hydraulic cylinder and the first guide rod, and the other side is connected to the horizontal push rod; The vertical push rod unit comprises a second guide mechanism, a second bottom plate and a vertical push rod for contacting the bottom of the workpiece. The second guide mechanism is used to guide the vertical push rod, and includes a second linear bearing installed on the base and a second guide rod passing therethrough. One side of the second base plate is connected to the second hydraulic cylinder and the second guide rod, and the other side is connected to the vertical push rod.

2. The crankshaft grinding center stand according to claim 1, characterized in that: The horizontal push rod unit further comprises a horizontal contact, one end of which is mounted on the horizontal push rod and the other end of which is used to contact with the workpiece; The vertical push rod unit further includes a vertical contact, one end of which is mounted to the vertical push rod and the other end of which is used to contact with a workpiece.

3. The crankshaft grinding center stand according to claim 1 or 2, characterized in that: The device further comprises a detection unit, wherein the detection unit comprises a sensor, and the sensor determines the position of the horizontal push rod through position detection.

4. The crankshaft grinding center stand according to claim 3, characterized in that: The detection unit further includes a sensing bracket, the sensing bracket is connected to the first bottom plate, and the sensor is fixedly connected to the base to determine the position of the horizontal push rod by detecting the position of the sensing bracket.

5. The crankshaft grinding center stand according to claim 3, characterized in that: The detection unit further comprises a sensor bracket, wherein the sensor bracket is fixed to the base, and the sensor is mounted on the sensor bracket.

6. The crankshaft grinding center stand according to claim 1 or 2, characterized in that: The first guide mechanism and the second guide mechanism further include a first bearing mounting seat for accommodating the first linear bearing and a second bearing mounting seat for accommodating the second linear bearing, respectively, and the first bearing mounting seat and the second bearing mounting seat are both connected to the base.

7. The crankshaft grinding center stand according to claim 1 or 2, characterized in that: The hydraulic system further comprises an oil circuit blocking plate, which is mounted to the base. An oil circuit passage is formed in the oil circuit blocking plate and communicates with the oil circuit passage in the base so that the first hydraulic cylinder and the second hydraulic cylinder are connected in series.

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