A vibration suppression device and processing method for deep hole boring of a cylinder head valve seat hole

Abstract

This invention relates to the field of diesel engine cylinder head boring technology, and provides a vibration suppression device and processing method for deep hole boring of cylinder head valve seat holes. The device includes a boring bar with multiple sets of support components evenly distributed circumferentially. Each support component includes a first cavity, a second cavity, and a third cavity within the boring bar. A counterweight and a first sealing piston are located in the first cavity. A matching second sealing piston is located in the second cavity. A support column is slidably disposed in the third cavity. A lever-type linkage component is also provided between the support column and the second sealing piston. Rotation of the boring bar causes the counterweight to slide under centrifugal force, thereby contacting and moving the first sealing piston. The lever-type linkage component amplifies the force applied to the support column, causing the end of the support column to move out of the third cavity and abut against the wall of the machined valve seat hole, thus suppressing vibration of the boring bar.

Description

Technical Field

[0001] This invention relates to the field of diesel engine cylinder head boring technology, specifically a vibration suppression device and processing method for deep hole boring of cylinder head valve seat holes. Background Technology

[0002] The cylinder head of a marine diesel engine is one of the core components of the engine. The machining accuracy of its valve seat bore directly affects the cylinder sealing, combustion chamber operation, and overall engine reliability. This type of valve seat bore usually has the structural characteristics of a large hole depth and a relatively small hole diameter, which is a typical feature of deep hole machining. In actual boring, in order to ensure that the tool can reach the bottom of the hole and complete the cutting of the entire length, the boring bar must have a sufficiently long overhang. Its length-to-diameter ratio is large, which leads to a significant decrease in both static and dynamic stiffness.

[0003] Under narrow bore conditions, the remaining space inside the bore is extremely limited. In traditional boring, in order to suppress the cutting vibration of long overhanging boring bars, methods such as adding intermediate support sleeves, guide strips, or auxiliary supports that contact the bore wall are often used to improve the rigidity of the boring bar. However, for small-diameter deep holes such as cylinder head valve seat holes, the annular gap between the bore wall and the boring bar is insufficient to accommodate the active support structure. After the boring bar enters the bore, it is completely in a cantilevered state without support. The dynamic changes in cutting force during boring can easily cause the boring bar to vibrate, resulting in obvious oscillation phenomenon and seriously reducing the quality of bore machining.

[0004] Therefore, this invention proposes a vibration suppression device and processing method for deep hole boring of cylinder head valve seat holes to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a vibration suppression device and processing method for deep hole boring of cylinder head valve seat holes, so as to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A vibration suppression device for deep hole boring of cylinder head valve seat holes includes a boring bar. Multiple sets of support components are evenly arranged circumferentially on the boring bar. Each support component includes a first cavity, a second cavity, and a third cavity disposed within the boring bar. The third cavity is located at the front end of the boring bar. A counterweight is slidably disposed in the first cavity along the radial direction of the boring bar. A matching first sealing piston is also disposed in the first cavity. A connecting air passage is provided between the first and second cavities. A matching second sealing piston is disposed in the second cavity. A support column is slidably disposed in the third cavity, and the support column is located away from the first cavity. A ball bearing is embedded at one end of the bottom side of the three-chamber channel. A lever-type linkage component is also provided between the support column and the second sealing piston. The rotation of the boring bar causes the counterweight to slide under the action of centrifugal force, thereby contacting the first sealing piston and driving it to move accordingly. Then, air is injected into the second chamber, causing the second sealing piston to move along the direction of the second chamber. The lever-type linkage component is linked and the lever action is used to amplify the force on the support column, so that the end of the support column away from the bottom side of the third chamber moves out of the third chamber and abuts against the wall of the machined valve seat hole to form support, thereby achieving the effect of suppressing the vibration of the boring bar.

[0007] In one alternative embodiment: the lever-type linkage component includes a fourth cavity with both ends communicating with the second cavity and the third cavity respectively, and a transmission rod hinged in the fourth cavity. The two ends of the transmission rod are respectively located between the support column and the bottom side of the third cavity and between the second sealing piston and the bottom side of the second cavity. The length of the rod segment between the end of the transmission rod located between the support column and the bottom side of the third cavity and its hinge point is less than the length of the rod segment between the end of the transmission rod located between the second sealing piston and the bottom side of the second cavity and its hinge point.

[0008] In one alternative: both the support column and the second sealing piston are provided with rollers whose treads contact the transmission rod.

[0009] In one alternative: several elastic elements are provided between the bottom side of the third cavity and the support column, so that the support column is located in the third cavity when the boring bar is not rotating.

[0010] In one alternative: a sealing ring is also provided on the inner wall of the third cavity to seal the gap between the support column and the inner wall of the third cavity.

[0011] In one alternative: the end of the support column away from the bottom of the third cavity is provided with a flexible scraper on both sides of the ball. The side of the scraper away from the support column is higher than the outer vertex of the ball, and is used to pre-scrape away the chips on the rolling path of the support column along the wall of the machined valve seat hole.

[0012] In one alternative: the support assembly further includes a channel for communicating the first cavity with the outside, the connection point between the channel and the interior of the first cavity being located on the side of the first cavity away from the air guide channel.

[0013] A method for deep boring of cylinder head valve seat holes, employing any of the vibration suppression devices described in the above-mentioned technical solutions, includes the following steps: S1: Attach the boring bar of the target specification to the front end of the boring bar, and then connect the tail end of the boring bar to the spindle of the boring machine; S2: The boring bar drives the boring tool into the cylinder head valve seat hole. During the rotating boring process, the counterweight slides radially along the boring bar under the action of centrifugal force, thereby contacting the first sealing piston and causing it to move accordingly. During the movement of the first sealing piston, air is injected into the second cavity, causing the second sealing piston to move along the direction of the second cavity. Through the linkage of the lever-type linkage component, the force on the support column is amplified by the lever action, causing the end of the support column away from the bottom side of the third cavity to move out of the third cavity and abut against the wall of the machined valve seat hole to form support, suppressing the vibration of the boring bar.

[0014] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows: During the rotary boring process, the counterweight slides radially along the boring bar under the action of centrifugal force, thereby contacting the first sealing piston and causing it to move accordingly. During the movement of the first sealing piston, air is injected into the second cavity, causing the second sealing piston to move along the direction of the second cavity. Through the linkage of the lever-type linkage component, the force on the support column is amplified by the lever action, causing the end of the support column away from the bottom side of the third cavity to move out of the third cavity and abut against the wall of the valve seat hole being machined, forming a stable support, thereby achieving the effect of suppressing the vibration of the boring bar and ensuring the machining quality of the cylinder head valve seat hole.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Furthermore, these drawings and textual descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to specific embodiments.

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of a cross section (partial section) of an embodiment of the present invention.

[0019] Figure 3 This is a side sectional view of an embodiment of the present invention.

[0020] Figure 4 for Figure 2 Enlarged view of point A in the middle.

[0021] Figure 5 for Figure 2 Enlarged view of section B in the middle.

[0022] Figure 6 This is a schematic diagram of the transmission rod in an embodiment of the present invention.

[0023] Figure reference numerals: 1-Boiling tool, 2-Boiling rod, 3-First cavity, 4-Counterweight, 5-First sealing piston, 6-Lever-type linkage component, 601-Fourth cavity, 602-Transmission rod, 603-Roller, 7-Third cavity, 8-Support column, 9-Ball, 10-Scraper, 11-Elastic component, 12-Sealing ring, 13-Second cavity, 14-Second sealing piston, 15-Air guide channel. Detailed Implementation

[0024] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0025] Please see Figures 1-5 A vibration suppression device for deep hole boring of cylinder head valve seat holes includes a boring bar 2. Multiple sets of support components are evenly arranged circumferentially on the boring bar 2. Each support component includes a first cavity 3, a second cavity 13, and a third cavity 7 disposed within the boring bar 2. The third cavity 7 is located at the front end of the boring bar 2 (i.e., the end closest to the boring tool). A counterweight 4 is slidably disposed radially in the first cavity 3 along the boring bar 2. A suitable first sealing piston 5 is also disposed in the first cavity 3. A connecting air passage 15 is provided between the first cavity 3 and the second cavity 13. A suitable second sealing piston 14 is disposed in the second cavity 13. A support column 8 is slidably disposed in the third cavity 7. A ball bearing 9 is embedded at one end of the support column 8 away from the bottom side of the third cavity 7. A lever-type linkage component 6 is also provided between the support column 8 and the second sealing piston 14. The rotation of the boring bar 2 causes the counterweight 4 to slide under the action of centrifugal force, thereby contacting the first sealing piston 5 and driving it to move accordingly. Then, air is injected into the second cavity 13, causing the second sealing piston 14 to move along the direction of the second cavity 13. The lever-type linkage component 6 is linked and the lever action is used to amplify the force on the support column 8, so that the end of the support column 8 away from the bottom side of the third cavity 7 moves out of the third cavity 7 and abuts against the wall of the machined valve seat hole to form support, thereby achieving the effect of suppressing the vibration of the boring bar 2.

[0026] It should be noted that this vibration suppression device is applicable to the centering boring mode, that is, the rotation axis of the boring bar 2 coincides with the center line of the cylinder head valve seat hole to be machined, and the boring bar 2 only rotates around its own axis to perform deep hole boring action; the tail end of the boring bar 2 (i.e. the end away from the boring tool) is clamped in the spindle taper hole of the boring machine through the tool holder and rotated by the spindle, and the axial feed motion of the boring bar 2 is driven by the machine tool's feed mechanism (such as the spindle box, slide or worktable).

[0027] The boring bar 2 drives the boring tool into the cylinder head valve seat hole (the cylinder head valve seat hole is usually formed by a two-step process of rough boring to leave a allowance and fine boring to shape it to size, that is, rough machining is first used to remove most of the allowance, and then fine boring tool is used to perform micro-cutting on the hole wall to achieve high precision of the hole diameter, high surface quality and coaxiality with the valve guide hole). During the rotating boring process, the counterweight 4 slides radially along the boring bar 2 under the action of centrifugal force, thereby contacting the first sealing piston 5 and driving it to move accordingly. During the movement of the first sealing piston 5, air is injected into the second cavity 13, causing the second sealing piston 14 to move along the second cavity 13. The cavity 13 moves, and through the lever linkage component 6, the force on the support column 8 is amplified by the lever action (that is, the force driven by the air pressure of the second sealing piston 14 is amplified by the lever action to drive the support column 8 and subsequently maintain a large support force), so that the end of the support column 8 away from the bottom side of the third cavity 7 moves out of the third cavity 7 and abuts against the wall of the machined valve seat hole to form a stable support (the extension length of the support column 8 can adapt to the hole diameter change during the boring process of the cylinder head valve seat hole), achieving the effect of suppressing the vibration of the boring bar 2 and ensuring the machining quality of the cylinder head valve seat hole.

[0028] Furthermore, the supporting assembly also includes a channel (not shown in the figure) for connecting the first cavity 3 with the outside (outside atmosphere). The connection point between the channel and the inside of the first cavity 3 is located on the side of the first cavity 3 away from the air guide channel 15, balancing the air pressure inside the first cavity 3, so that the first sealing piston 5 can move.

[0029] Furthermore, a sealing ring 12 is provided on the inner wall of the third cavity 7 to seal the gap between the support column 7 and the inner wall of the third cavity 7. During the boring process, cutting fluid will be sprayed and chips will be generated. By setting the sealing ring 12, the cutting fluid and chips are prevented from seeping into the third cavity 7.

[0030] Furthermore, at the end of the support column 8 away from the bottom side of the third cavity 7, located on both sides of the ball 9, there is also a flexible scraper 10 (the scraper 10 runs parallel to the axis of the boring bar 2 and can be made of flexible materials such as rubber). The side of the scraper 10 away from the support column 8 is higher than the outer vertex of the ball 9, which is used to pre-scrape away the chips on the rolling path of the support column 8 along the wall of the valve seat hole being machined, so as to avoid the presence of chips (the ball 9 is rolled on the cutting) causing the support column 8 to bounce.

[0031] Please participate Figure 2 , Figures 4-6 In one embodiment of the present invention, the lever-type linkage component 6 includes a fourth cavity 601 with both ends connected to the second cavity 13 and the third cavity 7 respectively, and a transmission rod 602 hinged in the fourth cavity 601. The two ends of the transmission rod 602 are located between the support column 8 and the bottom side of the third cavity 7 and between the second sealing piston 14 and the bottom side of the second cavity 13 respectively. The length of the rod segment between the end of the transmission rod 602 located between the support column 8 and the bottom side of the third cavity 7 and its hinge point is less than the length of the rod segment between the end of the transmission rod 602 located between the second sealing piston 14 and the bottom side of the second cavity 13 and its hinge point (i.e., the length of the power arm is greater than the resistance arm, thereby amplifying the torque).

[0032] Both the support column 8 and the second sealing piston 14 are equipped with rollers 603 whose treads contact the transmission rod 602.

[0033] In this embodiment, the lever action is used to amplify the force applied to the support column 8, so that the end of the support column 8 away from the bottom side of the third cavity 7 abuts against the wall of the valve seat hole being machined, forming a greater force support, ensuring the stability of the boring bar 2 during the boring process, and thus achieving the effect of vibration suppression.

[0034] Furthermore, in this embodiment, a number of elastic elements 11 are provided between the bottom side of the third cavity 7 and the support column 8 (the elastic elements 11 are springs, elastic ropes, etc. in the prior art, and the elastic coefficient is small, which can ensure that the support column 8 can be pulled back to the third cavity 7, thereby controlling the effect of the reverse force of the elastic elements 11 on the force reduction of the support column 8), which is used to make the support column 8 located in the third cavity 7 when the boring bar 2 is not rotating, and at the same time make the lever linkage component 6, the second sealing piston component 14 and the first sealing piston component 5 reset accordingly.

[0035] This invention provides a method for deep hole boring of cylinder head valve seat holes, employing a vibration suppression device for deep hole boring of cylinder head valve seat holes as described in any of the above technical solutions, comprising the following steps: S1: Attach the boring bar of the target specification to the front end of the boring bar 2, and then connect the tail end of the boring bar 2 to the spindle of the boring machine; S2: The boring bar 2 drives the boring tool into the cylinder head valve seat hole. During the rotating boring process, the counterweight 4 slides radially along the boring bar 2 under the action of centrifugal force, thereby contacting the first sealing piston 5 and driving it to move accordingly. During the movement of the first sealing piston 5, air is injected into the second cavity 13, causing the second sealing piston 14 to move along the direction of the second cavity 13. Through the linkage component 6, the lever action amplifies the force on the support column 8, causing the end of the support column 8 away from the bottom side of the third cavity 7 to move out of the third cavity 7 and abut against the wall of the machined valve seat hole to form support, suppressing the vibration of the boring bar 2.

[0036] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A vibration suppression device for deep hole boring of a cylinder head valve seat bore, comprising a boring bar (2), characterized in that The boring bar (2) is evenly provided with multiple sets of supporting components in the circumferential direction. The supporting components include a first cavity (3), a second cavity (13), and a third cavity (7) in the boring bar (2). The third cavity (7) is located at the front end of the boring bar (2). A counterweight (4) is slidably provided in the first cavity (3) along the radial direction of the boring bar (2). A matching first sealing piston (5) is also provided in the first cavity (3). A connecting air passage (15) is provided between the first cavity (3) and the second cavity (13). A matching second sealing piston (14) is provided in the second cavity (13). A supporting column (8) is slidably provided in the third cavity (7). The supporting column (8) is located away from the third cavity. A ball bearing (9) is embedded at one end of the bottom side of the channel (7). A lever-type linkage component (6) is also provided between the support column (8) and the second sealing piston (14). The rotation of the boring bar (2) causes the counterweight (4) to slide under the action of centrifugal force, thereby contacting the first sealing piston (5) and driving it to move accordingly. Then, air is injected into the second cavity (13), causing the second sealing piston (14) to move along the direction of the second cavity (13). The lever-type linkage component (6) amplifies the force on the support column (8), causing the end of the support column (8) away from the bottom side of the third cavity (7) to move out of the third cavity (7) and abut against the wall of the machined valve seat hole to form support, thereby suppressing the vibration of the boring bar (2).

2. The vibration suppressing device for deep hole boring of a cylinder head valve seat hole according to claim 1, characterized by The lever-type linkage component (6) includes a fourth cavity (601) with both ends connected to the second cavity (13) and the third cavity (7) respectively, and a transmission rod (602) hinged in the fourth cavity (601). The two ends of the transmission rod (602) are located between the support column (8) and the bottom side of the third cavity (7) and between the second sealing piston (14) and the bottom side of the second cavity (13) respectively. The length of the rod segment between the end of the transmission rod (602) located between the support column (8) and the bottom side of the third cavity (7) and its hinge point is less than the length of the rod segment between the end of the transmission rod (602) located between the second sealing piston (14) and the bottom side of the second cavity (13) and its hinge point.

3. The vibration suppression device for deep hole boring of cylinder head valve seat holes according to claim 2, characterized in that, Both the support column (8) and the second sealing piston (14) are provided with rollers (603) whose treads contact the transmission rod (602).

4. The vibration suppression device for deep hole boring of cylinder head valve seat holes according to claim 1, characterized in that, Several elastic elements (11) are also provided between the bottom side of the third cavity (7) and the support column (8) to ensure that the support column (8) is located in the third cavity (7) when the boring bar (2) is not rotating.

5. The vibration suppression device for deep hole boring of cylinder head valve seat holes according to claim 1, characterized in that, The inner wall of the third cavity (7) is also provided with a sealing ring (12) for sealing the gap between the support column (8) and the inner wall of the third cavity (7).

6. The vibration suppression device for deep hole boring of cylinder head valve seat holes according to claim 1, characterized in that, The end of the support column (8) away from the bottom of the third cavity (7) is provided with a flexible scraper (10) on both sides of the ball (9). The side of the scraper (10) away from the support column (8) is higher than the outer vertex of the ball (9) and is used to scrape off the chips on the rolling path of the support column (8) along the wall of the valve seat hole to be processed.

7. The vibration suppression device for deep hole boring of cylinder head valve seat holes according to claim 1, characterized in that, The supporting assembly also includes a channel for communicating the first cavity (3) with the outside, the connection point between the channel and the interior of the first cavity (3) being located on the side of the first cavity (3) away from the air guide channel (15).

8. A method for deep boring of cylinder head valve seat holes, employing the vibration suppression device for deep boring of cylinder head valve seat holes as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Attach the boring bar (2) to the front end of the boring bar (2) with the target specification boring tool, and then connect the tail end of the boring bar (2) to the spindle of the boring machine; S2: The boring bar (2) drives the boring tool into the cylinder head valve seat hole. During the rotating boring process, the counterweight (4) slides radially along the boring bar (2) under the action of centrifugal force, thereby contacting the first sealing piston (5) and driving it to move accordingly. During the movement of the first sealing piston (5), air is injected into the second cavity (13), causing the second sealing piston (14) to move along the second cavity (13). Through the linkage component (6), the linkage is activated and the lever action is used to amplify the force on the support column (8), so that the end of the support column (8) away from the bottom side of the third cavity (7) moves out of the third cavity (7) and abuts against the wall of the machined valve seat hole to form support, suppressing the vibration of the boring bar (2).

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