Differential indexing mechanism of universal milling head

Abstract

The invention relates to the field of milling head equipment for machine tools, and discloses a differential indexing mechanism of a universal milling head, which comprises a fixed body, a rotating body and a middle body, and the middle body is arranged between the fixed body and the rotating body. The opposite end faces of the fixed body and the middle body are each provided with an end-toothed disc with the matched tooth shape and the tooth number of Z1, the minimum indexing angle delta 1 is 360 / Z1, the opposite end faces of the rotating body and the middle body are each provided with an end-toothed disc with the matched tooth shape and the tooth number of Z2, the minimum indexing angle delta 2 is 360 / Z2, and the tooth number Z1 and the tooth number Z2 are not equal in numerical value. The middle body and the rotating body can axially move along the central axis under the action of an oil cylinder, the middle body and the rotating body can radially rotate along the central axis under the driving of a motor, the two groups of end-toothed disc pairs are controlled to be engaged and disengaged, the indexing is realized through opposite differential rotation, the minimum indexing angle delta is equal to delta1-delta2, and the indexing position number P in the circumferential direction is equal to 360 / delta. The numerical value of the minimum indexing angle of the milling head is greatly reduced through differential indexing, positioning and locking are achieved through indexing of the end-toothed disc, the accuracy of rotation positioning precision and repeated positioning precision of the milling head is guaranteed, and meanwhile the mechanical strength is improved.

Description

Technical Field

[0001] The invention relates to the field of milling head equipment for machine tools, in particular to a differential indexing mechanism of a universal milling head. Background Art

[0002] The universal milling head is the core functional component of industrial machine tools and is widely used in pentahedron machining centers such as gantry, boring and milling. The minimum indexing angle and maximum torque output of the universal milling head are important technical indicators for measuring the machining capabilities of machine tools. The existing technology of universal milling head indexing locking mainly has two structural forms:

[0003] One type uses a motor drive with an encoder to achieve continuous indexing, and adopts an embracing or disc brake friction braking positioning and locking. This type of technology can achieve continuous indexing. The locking mechanism is sliding friction, the braking torque is small and it is easy to cause sliding displacement, resulting in loss of accuracy and limited torque output.

[0004] The other type is driven by a motor, with double end gear disc indexing and locking, and the end gear disc is positioned and locked, with high positioning accuracy and high torque output. Subject to the size limit of the universal milling head, such as within the circumference of Ø360mm, in order to ensure the tooth width and mechanical strength of the end gear disc, the number of teeth Z is generally ≤180, and the minimum indexing angle δ is ≥2°.

[0005] Universal milling heads require fine indexing angles and large torque output to meet the pentahedral processing and heavy cutting needs of gantry, boring and milling machines, etc. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a differential indexing mechanism for a universal milling head, and the present invention provides the following technical solutions:.

[0007] A differential indexing mechanism of a universal milling head comprises a fixed body, a rotating body and an intermediate body, wherein the intermediate body is arranged between the fixed body and the rotating body, and the central axes of the three coincide. The facing end faces of the fixed body and the intermediate body are both provided with end toothed discs with a tooth shape matching the number of teeth Z1, and the facing end faces of the rotating body and the intermediate body are both provided with end toothed discs with a tooth shape matching the number of teeth Z2, and the tooth numbers Z1 and Z2 of the end toothed discs are not equal in value.

[0008] The differential indexing mechanism of the universal milling head is characterized in that the fixed body is axially fixedly connected to the first piston rod, the first piston rod and the inner cavity of the rotating body form a cylinder body to form a first oil chamber, the rotating body is axially fixedly connected to the second piston rod, the second piston rod and the inner cavity of the third piston rod form a cylinder body to form a second oil chamber, the intermediate body is axially fixedly connected to the third piston rod, the third piston rod and the inner cavity of the fixed body form a cylinder body to form a third oil chamber.

[0009] Furthermore, the first oil chamber is kept in a pressurized state, the second oil chamber and the third oil chamber are kept in a depressurized state, and the end gear plate pair 4-5 and the end gear plate pair 6-7 are both in an engaged, positioned and locked state, which can ensure the accuracy of the indexing precision and provide sufficient mechanical strength to achieve large torque output.

[0010] Furthermore, the third oil chamber is kept in a pressurized state, the first oil chamber and the second oil chamber are kept in a depressurized state, the end gear disc pair 4-5 is in a disengaged state, the end gear disc pair 6-7 is in an engaged state, the fixed body is fixed in position, and the combination of the rotating body and the intermediate body can be radially rotated around the center axis for positioning and indexing under the drive of a servo motor, and the minimum rotation indexing angle δ1=360 / Z1.

[0011] Furthermore, the second oil chamber is kept in a pressurized state, the first oil chamber and the third oil chamber are kept in a depressurized state, the end gear disc pair 6-7 is in a disengaged state, the end gear disc pair 4-5 is in an engaged state, the position of the combination of the fixed body and the central body is fixed, and the rotating body can be radially rotated around the central axis for positioning and indexing under the drive of a servo motor, and the minimum rotation indexing angle δ2=360 / Z2.

[0012] Further, the end toothed disc pair 4-5 is in a disengaged state, the end toothed disc pair 6-7 is in a meshing state, and the combination of the rotating body and the intermediate body rotates clockwise around the central axis by a minimum indexing angle δ1. The end toothed disc pair 6-7 is in a disengaged state, the end toothed disc pair 4-5 is in a meshing state, and the rotating body rotates counterclockwise around the central axis by a minimum indexing angle δ2. The end toothed disc pair 4-5 and the end toothed disc pair 6-7 are both in a meshing state, and the minimum indexing angle δ=δ1-δ2 that can be obtained by the differential indexing mechanism.

[0013] In the differential indexing mechanism of the universal milling head described above, the number of teeth Z1 of the end gear disc pair 4-5 is 120, the minimum indexing angle δ1 is 3°, the number of teeth Z2 of the end gear disc pair 6-7 is 144, the minimum indexing angle δ2 is 2.5°, the minimum indexing angle δ of the differential indexing mechanism is 0.5°, which is an accurate value, and the number of indexing positions P in the circumferential direction is 720.

[0014] Furthermore, the number of teeth Z1 of the end gear pair 4-5 is 144, the minimum indexing angle δ1 is 2.5°, the number of teeth Z2 of the end gear pair 6-7 is 150, the minimum indexing angle δ2 is 2.4°, the minimum indexing angle δ of the differential indexing mechanism is 0.1°, which is an accurate value, and the number of indexing positions P in the circumferential direction is 3600.

[0015] Furthermore, the number of teeth Z1 of the end gear pair 4-5 is 119, and the minimum indexing angle δ1 is 3.025210°. The number of teeth Z2 of the end gear pair 6-7 is 121, and the minimum indexing angle δ2 is 2.975207°. δ1-δ2=0.050003°, which is not an exact value. The precise rounding method is adopted to set the minimum indexing angle δ of the differential indexing mechanism to 0.05°. The angular error is (δ1-δ2-δ) / δ<0.01%. The influence of the error on the accuracy can be ignored. The number of indexing positions P in the circumferential direction is 7200.

[0016] Furthermore, the number of teeth Z1 of the end gear pair 4-5 is 134, and the minimum indexing angle δ1 is 2.686567°. The number of teeth Z2 of the end gear pair 6-7 is 135, and the minimum indexing angle δ2 is 2.666667°. δ1-δ2=0.0199005°, which is not an exact value. The precise rounding method is adopted to set the minimum indexing angle δ of the differential indexing mechanism to 0.02°. The angular error is (δ1-δ2-δ) / δ<0.5%. The influence of the error on the accuracy can be ignored. The number of indexing positions P in the circumferential direction is 18,000.

[0017] Compared with the prior art, the present invention provides a differential indexing mechanism for a universal milling head, which has the following beneficial effects:

[0018] The present invention forms two sets of end toothed disc pairs with different numbers of teeth through a fixed body, a rotating body and an intermediate body triplet, and utilizes the opposite differential indexing mechanism of the two sets of end toothed discs to refine the minimum indexing angle, overcome the current limitation of the minimum indexing of the end toothed discs, and improve the processing capacity of the universal milling head. At the same time, after the indexing is completed, the end toothed discs are positioned and locked to ensure the accuracy of positioning accuracy and repeated positioning accuracy, while improving the mechanical strength and the large torque output performance of the universal milling head. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of a 45° universal AB axis milling head embodiment disclosed in the present invention;

[0020] Figure 2 It is a schematic diagram of the exploded structure of the triplet end gear disc pair disclosed in the present invention;

[0021] Figure 3 It is a schematic diagram of the structure of the indexing positioning locking disclosed by the present invention;

[0022] Figure 4 It is a structural schematic diagram of the end gear disc pair 4-5 disclosed in the present invention when it is disengaged and the end gear disc pair 6-7 is engaged;

[0023] Figure 5It is a structural schematic diagram of the end gear disc pair 4-5 disclosed in the present invention when it is engaged and the end gear disc pair 6-7 is disengaged.

[0024] In the figure: 1, fixed body; 2, rotating body; 3, intermediate body; 4, first end gear disc; 5, second end gear disc; 6, third end gear disc; 7, fourth end gear disc; 8, first piston rod; 9, second piston rod; 10, third piston rod; 11, first oil chamber; 12, second oil chamber; 13, third oil chamber. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 , a structural schematic diagram of a differential indexing mechanism of a universal milling head in a 45° universal AB axis milling head embodiment, and the local sectional views C and C' positions are the position layout of the differential indexing mechanism in the universal milling head.

[0027] See also Figure 2 A differential indexing mechanism of a universal milling head comprises a triplet consisting of a fixed body 1, a rotating body 2 and an intermediate body 3, the central axes of the three coincide, and the intermediate body 3 is arranged between the fixed body 1 and the rotating body 2; the end face of the fixed body 1 facing the intermediate body 3 is provided with a first end toothed disc 4 with a tooth number Z1, the end face of the intermediate body 3 facing the fixed body 1 is provided with a second end toothed disc 5 with a tooth number Z1, the tooth shapes of the first end toothed disc 4 and the second end toothed disc 5 match to form an end toothed disc pair 4-5; the end face of the rotating body 2 facing the intermediate body 3 is provided with a third end toothed disc 6 with a tooth number Z2, the end face of the intermediate body 3 facing the rotating body 2 is provided with a fourth end toothed disc 7 with a tooth number Z2, the tooth shapes of the third end toothed disc 6 and the fourth end toothed disc 7 match to form an end toothed disc pair 6-7.

[0028] See also Figure 3-5 The fixed body 1 is axially fixedly connected to the first piston rod 8, and the first piston rod 8 and the inner cavity of the rotating body 2 form a cylinder body to form a first oil chamber 11 with a stroke of S; the rotating body 2 is axially fixedly connected to the second piston rod 9, and the second piston rod 9 and the inner cavity of the third piston rod 10 form a cylinder body to form a second oil chamber 12 with a stroke of S; the intermediate body 3 is axially fixedly connected to the third piston rod 10, and the third piston rod 10 and the inner cavity of the fixed body 1 form a cylinder body to form a third oil chamber 13 with a stroke of S.

[0029] See also Figure 3The first oil chamber 11 is kept in a pressurized state, and the second oil chamber 12 and the third oil chamber 13 are kept in a depressurized state, so that the end gear plate pair 4-5 and the end gear plate pair 6-7 are in a meshing, positioning and locking state, and the fixed body 1, the rotating body 2 and the intermediate body 3 triplet form a combination.

[0030] See also Figure 4 , the third oil chamber 13 remains in a pressurized state, the first oil chamber 11 and the second oil chamber 12 remain in a depressurized state, under the action of the third piston rod 10, the rotating body 2 and the intermediate body 3 combination undergoes an axial displacement S, the end gear pair 4-5 is axially disengaged by a spacing Δ, and the end gear pair 6-7 remains in a meshing state. Driven by the servo motor, the rotating body 2 and the intermediate body 3 combination can be radially rotated and indexed relative to the fixed body 1 around the center axis, and the minimum rotation indexing angle δ1=360 / Z1.

[0031] See also Figure 5 , the second oil chamber 12 remains in a pressurized state, the first oil chamber 11 and the third oil chamber 13 remain in a depressurized state, under the action of the third piston rod 10, the intermediate body 3 undergoes an axial displacement S, the end gear pair 4-5 is in a meshing state, and the end gear pair 6-7 is axially disengaged by a spacing Δ. Driven by the servo motor, the rotating body 2 can be radially rotated and indexed around the center axis relative to the combination of the fixed body 1 and the intermediate body 3, and the minimum rotation indexing angle δ2=360 / Z2.

[0032] See also Figure 3-5 , a differential indexing mechanism of a universal milling head, the end gear pair 4-5 is in a disengaged state, the end gear pair 6-7 is in an engaged state, and the differential indexing mechanism rotates clockwise by an angle δ1; the end gear pair 4-5 is in an engaged state, the end gear pair 6-7 is in a disengaged state, and the differential indexing mechanism rotates counterclockwise by an angle δ2; the end gear pair 4-5 and the end gear pair 6-7 are both in an engaged state, and the minimum indexing angle of the differential indexing mechanism δ=δ1-δ2.

[0033] The present invention discloses a differential indexing mechanism of a universal milling head, wherein the minimum indexing angle is δ, the number of indexing positions in the circumferential direction is P=360 / δ, and the indexing angle A in the circumferential direction is an integer multiple of δ. In a specific embodiment, if the number of teeth Z1 of the end gear disc pair 4-5 is 120, the minimum indexing angle δ1 is 3°, the number of teeth Z2 of the end gear disc pair 6-7 is 144, the minimum indexing angle δ2 is 2.5°, the minimum indexing angle δ of the differential indexing mechanism is 0.5°, and the number of indexing positions P in the circumferential direction is 720. If the differential indexing mechanism needs to rotate an angle A of 88.5° in the circumferential direction, the differential indexing mechanism is set to rotate n1 minimum indexing angles δ1 clockwise and n2 minimum indexing angles δ2 counterclockwise, and the calculation formula is as follows:

[0034] n1=INT(A / δ1)+(A-INT(A / δ1)*δ1) / (δ1-δ2)=32, n2=(A-INT(A / δ1)*δ1) / (δ1-δ2)=3.

[0035] It should be noted that in this article, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present application.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A differential indexing mechanism of a universal milling head, comprising a fixed body (1), a rotating body (2) and an intermediate body (3), wherein the intermediate body (3) is arranged between the fixed body (1) and the rotating body (2), and the central axes of the three coincide with each other; the facing end surfaces of the fixed body (1) and the intermediate body (3) are both provided with end toothed discs with a tooth shape matching the number of teeth Z1; the facing surfaces of the rotating body (2) and the intermediate body (3) are both provided with end toothed discs with a tooth shape matching the number of teeth Z2; the tooth numbers Z1 and Z2 of the end toothed discs are not equal.

2. The differential indexing mechanism of a universal milling head according to claim 1, characterized in that: The fixed body (1) is axially fixedly connected to the first piston rod (8); the first piston rod (8) and the inner cavity of the rotating body (2) form a cylinder body to form a first oil chamber (11); The rotating body (2) and the second piston rod (9) are axially fixedly connected, and the inner cavities of the second piston rod (9) and the third piston rod (10) form an oil cylinder body to form a second oil chamber (12); The intermediate body (3) and the third piston rod (10) are axially fixedly connected, and the third piston rod (10) and the inner cavity of the fixed body (1) form an oil cylinder body to form a third oil chamber (13).

3. The differential indexing mechanism of a universal milling head according to claim 1, characterized in that: The first oil chamber (11) is kept in a pressurized state, and the second oil chamber (12) and the third oil chamber (13) are kept in a depressurized state. Under the action of the oil cylinder, the end gear disc pair (4-5) and the end gear disc pair (6-7) are both in a meshing, positioning and locking state. The third oil chamber (13) is kept in a pressurized state. The first oil chamber (11) and the second oil chamber (12) are kept in a depressurized state. Under the action of the oil cylinder, the first end gear disc (4) and the second end gear disc (5) are in a disengaged state, with an axial disengagement interval Δ. The third end gear disc (6) and the fourth end gear disc (7) are in a meshing state. The rotating body (2) and the intermediate body (3) can be radially rotated and positioned around the central axis through the meshing assembly of the end gear disc pair (6-7) under the drive of the motor. The second oil chamber (12) is kept in a pressurized state. The first oil chamber (11) and the third oil chamber (13) are kept in a depressurized state. Under the action of the oil cylinder, the third end gear disc (6) and the fourth end gear disc (7) are in a disengaged state, with an axial disengagement interval Δ. The first end gear disc (4) and the second end gear disc (5) are in an engaged state. The rotating body (2) can be radially rotated around the central axis to position under the drive of the motor.

4. The differential indexing mechanism of a universal milling head according to claim 1, characterized in that: The first end gear disc (4) and the second end gear disc (5) are in a disengaged state, the third end gear disc (6) and the fourth end gear disc (7) are in an engaged state, and under the drive of the motor, the rotating body (2) and the intermediate body (3) assembly rotates clockwise around the central axis by an angle δ1=360 / Z1; The first end gear disc (4) and the second end gear disc (5) are in a meshing state, the third end gear disc (6) and the fourth end gear disc (7) are in a disengaged state, and under the drive of the motor, the rotating body (2) rotates counterclockwise around the central axis at an angle δ2=360 / Z2; The minimum indexing angle of the differential indexing mechanism is δ=δ1-δ2, and the number of indexing positions in the circumferential direction is P=360 / δ.

5. The differential indexing mechanism of a universal milling head according to claim 1, characterized in that: The number of teeth Z1 of the end gear disc pair (4-5) is 120, the number of teeth Z2 of the end gear disc pair (6-7) is 144, the minimum indexing angle δ of the differential indexing mechanism is 0.5°, and the number of indexing positions P in the circumferential direction is 720; The number of teeth Z1 of the end gear plate pair (4-5) is 144, the number of teeth Z2 of the end gear plate pair (6-7) is 150, the minimum indexing angle δ of the differential indexing mechanism is 0.1°, and the number of indexing positions P in the circumferential direction is 3600; The number of teeth Z1 of the end gear plate pair (4-5) is 119, the number of teeth Z2 of the end gear plate pair (6-7) is 121, the minimum indexing angle δ of the differential indexing mechanism is 0.05°, and the number of indexing positions P in the circumferential direction is 7200; The number of teeth Z1 of the end gear disc pair (4-5) is 134, the number of teeth Z2 of the end gear disc pair (6-7) is 135, the minimum indexing angle δ of the differential indexing mechanism is 0.02°, and the number of indexing positions P in the circumferential direction is 18,000.

6. The differential indexing mechanism of a universal milling head according to claim 1, characterized in that: The differential indexing mechanism is applied to the 45° universal AB axis milling head. Through the disengagement and rotation of the end gear plate pair, a fine indexing angle of the 45° universal AB axis milling head can be achieved, thereby increasing the number of indexing positions. The differential indexing mechanism is applied to a 45° universal AB axis milling head. Through the indexing, positioning and locking of the end gear disc pair, the overall accuracy and mechanical strength of the 45° universal AB axis milling head can be improved, and a large torque output can be achieved.

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