Machine tool machining head assembly and machine tool

Abstract

The invention relates to the field of machine tool machining assemblies, in particular to a machine tool machining head assembly and a machine tool, the machine tool machining head assembly comprises a sliding saddle, a ram, a protective cover, a guide rail and a linkage mechanism, the guide rail is provided with an obliquely-arranged first path, and the inclination mode of the first path is that the height gradually rises in the extending direction of the ram. The hinged joint of the driving part and the transmission part can slide along the guide rail. The maximum extending stroke of the protective cover and the length of the driving part and the transmission part meet the preset relation, so that the linkage mechanism can push the protective cover to enter the first state of moving along with the ram, even if the ram extends out of the saddle for a long distance, the protective cover can still protect a main shaft on the ram, and the service life of the main shaft is prolonged. And the hidden danger that splashing cutting fluid and cuttings enter the sliding saddle is reduced.

Description

Technical Field

[0001] This invention relates to the field of machine tool processing components, and more specifically, to a machine tool processing head assembly and a machine tool. Background Technology

[0002] In horizontal machining centers, the spindle box employs a telescopic ram structure, offering advantages such as flexible movement and light weight. During the cutting process, protective devices are typically installed to prevent contamination of the spindle box by chips and cutting debris.

[0003] Existing technical solutions employ bellows-structure protective devices for telescopic ram structures to provide maximum protection for the extended ram and spindle portion. For example, patent document CN218800914U provides a bellows protective structure for a ram, which includes a bellows, a left guard, a right guard, a transition sheet metal cover, and a flange. The left and right guards are respectively covered and fixed to both sides of the bottom surface of the saddle. The bellows and the transition sheet metal cover are respectively fitted onto the outside of the ram. The upper end of the transition sheet metal cover is fixedly connected to the left and right guards, and the lower end of the transition sheet metal cover is fixedly connected to the upper end of the bellows. The lower end of the bellows is fixedly connected to the flange. The extension direction of the bellows is along the Z-axis of the machine tool, and the flange is fixed to the bottom end of the ram.

[0004] However, this bellows-shaped protective structure is complex, requiring multiple components such as the bellows, left guard, right guard, transition sheet metal cover, and flange for connection and protection. This type of protective structure can easily lead to splashed cutting fluid and chips adhering to the folds of the bellows, posing a risk of damaging the guard and causing leakage. Summary of the Invention

[0005] To address one of the aforementioned problems, the present invention aims to provide a machine tool processing head assembly.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] On one hand, an embodiment of the present invention provides a machine tool machining head assembly, the machine tool including a saddle and a ram, the ram being slidably mounted on the saddle, and the machine tool linkage assembly further including:

[0008] The protective cover includes a protective plate arranged around the circumference of the slide, and the protective cover is located at the front part of the slide in the direction of its extension;

[0009] A guide rail is disposed on the side of the slide, and the guide rail has a first path that is inclined such that the inclination of the first path gradually increases in height along the extension direction of the slide; and,

[0010] The linkage mechanism includes a driving member, a transmission member, and a driven member that are hinged together in sequence. The end of the driving member away from the transmission member is hinged to the slide saddle, and the end of the driven member away from the transmission member is fixedly connected to the protective cover. The joint where the driving member and the transmission member are hinged together can slide along the guide rail.

[0011] The maximum extension stroke of the protective cover and the lengths of the driving and transmission components satisfy a preset relationship.

[0012] In some implementations, the maximum extension stroke Δx of the protective cover satisfies the following relationship:

[0013] Δx=|(a·cosa′+b·cosβ′)-(a·cosα+b·cosβ)|;

[0014] In the formula, a and b are the lengths of the driving component and the transmission component, respectively; α and α′ are the angles between the length direction of the driving component and the extension direction of the slide at the two moments when the protective cover begins to extend and ends to extend; β and β′ are the angles between the length direction of the transmission component and the extension direction of the slide at the two moments when the protective cover begins to extend and ends to extend.

[0015] In some implementations, the height difference Δh between the two ends of the first path satisfies the following relationship:

[0016] Δh=a·|sinα′-sinα|.

[0017] In some implementations, the length 'a' of the driving member and the length 'b' of the transmission member are equal, and the maximum extension stroke Δx of the protective cover satisfies the following relationship:

[0018] Δx = 2a·|cosα′-cosα|;

[0019] The ratio of the maximum extension stroke Δa of the protective cover to the height difference Δh between the two ends of the first path satisfies:

[0020]

[0021] In some embodiments, the guide rail also has a second path that connects to the first path, the second path extending in a direction parallel to the sliding direction of the slide, and the second path being located in front of or behind the first path in the extension direction of the slide.

[0022] In some embodiments, the guide rail also has a third path that connects to the first path, the third path extending in a direction parallel to the sliding direction of the slide, and the third path and the second path connecting to different ends of the first path respectively.

[0023] In some implementations, at least one of the junctions between the first and second paths and between the first and third paths is a smooth transition.

[0024] In some embodiments, the guide rail includes a guide groove with a groove structure, the driving component and the transmission component are hinged to each other by a pin, the width of the guide groove is adapted to the pin, one end of the pin is placed in the groove of the guide groove, and the pin is in sliding or rolling fit with the groove wall of the guide groove.

[0025] In some implementations, there are two linkage mechanisms, which are symmetrically arranged on both sides of the protective cover.

[0026] In some implementations, the first path is an arc-shaped path setting.

[0027] On the other hand, embodiments of the present invention also provide a machine tool, including a machine tool processing head assembly as described above, the machine tool further including a base and a column, the column being disposed on the base, and a slide saddle being vertically mounted on the column.

[0028] The beneficial effects of this invention include at least the following: the guide rail has a first path with an inclination, the inclination of which gradually increases in height along the extension direction of the slide. The joint where the driving member and the transmission member are hinged together can slide along the guide rail. The maximum extension stroke of the protective cover satisfies a preset relationship with the lengths of the driving member and the transmission member, enabling the linkage mechanism to push the protective cover into a first state that follows the movement of the slide. This ensures that even if the slide extends a considerable distance from the saddle, the protective cover can still protect the spindle on the slide, thereby reducing the risk of splashed cutting fluid and chips entering the interior of the saddle. Attached Figure Description

[0029] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0030] Figure 1 This is a schematic diagram of the structure of one embodiment of the machine tool processing head assembly in some embodiments of the present invention;

[0031] Figure 2 This is a schematic diagram of one embodiment of the machine tool processing head assembly in some embodiments of the present invention;

[0032] Figure 3 This is a schematic diagram illustrating the movement principle of the machine tool processing head assembly in some embodiments of the present invention;

[0033] Figure 4 This is a schematic diagram of the extended slide block structure in some embodiments of the present invention;

[0034] Figure 5 This is a cross-sectional view of a machine tool processing head assembly in some embodiments of the present invention.

[0035] The attached diagram is labeled as follows: 1-slide saddle, 2-slide bolster, 3-protective cover, 4-guide rail, 41-first path, 42-second path, 43-third path, 5-linkage mechanism, 51-driven component, 52-transmission component, 53-driving component, 54-hinged shaft, 6-guide plate, 7-main shaft, 8-protective shell, 9-scraper plate. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0037] refer to Figure 1 A machine tool machining head assembly according to a first aspect of the present invention includes: a slide saddle 1, a ram 2, a protective cover 3, a guide rail 4, and a linkage mechanism 5. The ram 2 is slidably mounted on the slide saddle 1. The protective cover 3 includes a protective plate arranged circumferentially around the ram 2 and is located at the front of the ram 2 in its extending direction. The guide rail 4 is located on the side of the ram 2 and has an inclined first path 41, the inclination of which gradually increases in height along the extending direction of the ram 2. The linkage mechanism 5 includes a driving member 53, a transmission member 52, and a driven member 51, which are hinged sequentially. The end of the driven member 51 away from the transmission member 52 is fixedly connected to the protective cover 3, and the end of the driving member 53 away from the transmission member 52 is hinged to the slide saddle 1. The joint where the driving member 53 and the transmission member 52 are hinged together can slide along the guide rail 4, and the joint where the driven member 51 and the transmission member 52 are hinged together can slide linearly relative to the slide saddle 1. The maximum extension stroke of the protective cover 3 and the lengths of the driving member 53 and the transmission member 52 satisfy a preset relationship, so that the linkage mechanism 5 can push the protective cover 3 into the first state of movement. In this first state, the protective cover 3 moves with the slide bolster 2.

[0038] Specifically, a through groove is provided on the sliding saddle 1, and the protective cover 3 and the sliding bolster 2 are located within the through groove. See details. Figure 4A main shaft 7 is provided on one side of the slide 2 in the extension direction, and a guide rail 4 is provided on the side of the slide 2. The protective cover 3 can be a through frame structure, with the main shaft 7 inserted inside the protective cover 3. The driven member 51, the transmission member 52, and the driving member 53 can all be connecting rods. One end of the driven member 51 is connected to the protective cover, and one end of the driving member 53 is hinged to the slide saddle 1. The hinge point between the transmission member 52 and the driving member 53 slides within the guide rail 4. The maximum extension stroke of the protective cover 3 and the lengths of the driving member 43 and the transmission member 52 satisfy a preset relationship, so that the linkage mechanism 43 can push the protective cover 3 into the first state of moving with the slide 2, so that even if the slide 2 extends a long distance from the slide saddle 1, the protective cover 3 can still protect the main shaft on the slide 2.

[0039] In one embodiment, reference Figures 1 to 3 The positional relationship of the protective shield before and after its movement is as follows:

[0040] The length of the driving component 43 is *a*, and the length of the transmission component 52 is *b*; α and α′ are the angles between the length direction of the driving component 43 and the extension direction of the slide block 2 at the two moments when the protective cover 3 begins and ends its extension, respectively; β and β′ are the angles between the length direction of the transmission component 52 and the extension direction of the slide block 2 at the two moments when the protective cover 3 begins and ends its extension, respectively; x1 is the projected length of the linkage mechanism 43 before it moves, x2 is the projected length of the linkage mechanism 43 after it moves, h1 is the projected height of the linkage mechanism 43 before it moves, and h2 is the projected height of the linkage mechanism 43 after it moves. From this, the following relationship can be obtained:

[0041] x2-x1=Δx,

[0042] h1-h2=Δh,

[0043] h1 = asinα,

[0044] h2=asinα′,

[0045] x1 = acosα + bcosβ,

[0046] x2 = acosα′ + bcosβ′,

[0047] In summary, the maximum extension stroke Δx of the protective cover 3 satisfies the following relationship:

[0048] Δx=|(a·cosα′+b·cosβ′)-(a·cosα+b·cosβ)|;

[0049] It can also be concluded that the height difference Δh between the two ends of the first path 41 satisfies the following relationship:

[0050] Δh=a·|sinα′-sinα|.

[0051] Furthermore, when the length a of the driving component 43 and the length b of the transmission component 52 are equal, then angle α is equal to angle β, and angle α′ is equal to angle β′. Therefore, the maximum extension stroke Δx of the protective cover 3 satisfies the following relationship:

[0052] Δx = 2a·|cosα′-cosα|

[0053] In this case, the ratio of the maximum extension stroke Δx of the protective cover 3 to the height difference Δh between the two ends of the first path 41 satisfies:

[0054]

[0055] In a more specific embodiment, based on the above relationship, the required length values ​​are assigned to the driving member 43 and the transmission member 52, and the angular positional relationship of the linkage mechanism 43 and the rod can be calculated. In practical applications, the size of Δh can be determined based on the actual dimensions of the slide 2 in the machine tool, and Δx can be confirmed based on the required movement length of the protective cover 3. A value of a or h1 is determined based on the relative position of the slide 2 and the slide saddle 1, and the angles α and β are calculated. It is understood that other variables can also be calculated using the angles and the length a of the driving member 43. For the design of the guide rail 4, the horizontal length in the guide rail 4 can be determined based on the stroke of the slide 2, and the vertical height of the guide rail 4 can be determined by Δh. To achieve intermittent displacement control, horizontal trajectories parallel to the movement direction of the slide 2 (i.e., the second path 42 and the third path 43) need to be added at the starting and ending points of the guide rail 4, or horizontal trajectories parallel to the slide 2 need to be added where intermittent movement is required. The intermediate trajectory (the first path 41) adopts a straight or curved inclined line segment, and the shape (slope and length) of the line segment determines the speed change and movement time of the driven member 51 and the protective cover 3. When the slide ram 2 moves at a constant speed, if the slope of the first path 41 remains unchanged, the protective cover 3 will move at approximately a constant speed. If the first path 41 is set as an arc-shaped curve with an upward convex shape (which can be set so that the curve slope is initially large and then decreases), the tunnel will move in a slow-to-fast manner. If the curve is concave (which can be set so that the curve slope is initially small and then increases), the tunnel will move in a fast-to-slow manner. The shorter the horizontal length of the curve, the shorter the movement time and the greater the impact; the longer the horizontal length of the curve, the longer the movement time and the smaller the impact. At the junction of the curved segment and the horizontal line segment, an arc is needed for a smooth transition to reduce the impact during the movement.

[0056] Furthermore, in one specific embodiment, before setting the guide rail 4, the motion trajectory of the hinge shaft 54 ​​can be simulated multiple times until a guide trajectory that meets the requirements is formed. For example, paint can be applied or applied to the inner side of the hinge shaft 54, and then the slide 2 can be driven. When the slide 2 moves in the extension direction, the paint on the hinge shaft 54 ​​will draw a motion trajectory on the guide plate 6, and then the guide rail 4 can be machined on the guide plate 6 along the motion trajectory.

[0057] In one embodiment, reference Figure 1 and Figure 4 The guide rail 4 also has a second path 42 that connects to the first path 41. The extension direction of the second path 42 is parallel to the sliding direction of the slide 2, and the second path 42 is located in front of the first path 41 in the extension direction of the slide 2 (e.g., Figure 1 , Figure 3 as well as Figure 4 (as shown) or behind. Specifically, the hinge point between the driving member 53 and the transmission member 52 moves within the guide rail, and this hinge point can be hinged by a pin (i.e., hinge shaft 54). When the hinge shaft 54 ​​enters the second path 42, since the second path 42 is horizontally set, the hinge shaft 54 ​​moves away from the protective cover 3 along the second path 42, which is the second state. In this second state, the transmission member 52 does not provide thrust to the driven member 51, so the protective cover 3 does not move relative to the slide saddle 1. Conversely, when the slide ram 2 moves away from the extension direction, the hinge shaft 54 ​​moves towards the extension direction within the guide rail 4. When the hinge shaft 54 ​​abuts against the left end of the second path 42, the end of the second path 42 will push the hinge shaft 54 ​​to move away from the slide saddle 1 towards the extension direction of the slide ram 2, and then the transmission member 52 pulls the driven member 51 to move the protective cover 3 away from the extension direction, so that the protective cover 3 returns to the position before it was pushed.

[0058] In one embodiment, reference Figure 1 and Figure 4 The guide rail 4 also has a third path 43 that connects to the first path 41. The extension direction of the third path 43 is parallel to the sliding direction of the slide 2, and the third path 43 and the second path 42 are respectively connected to different ends of the first path 41. Specifically, the guide rail 4 is set on a guide plate 6. The guide rail 4 includes a second path 42, a first path 41 and a third path 43 connected in sequence. The second path 42 and the third path 43 are parallel to the extension direction of the slide 2. The second path 42 and the third path 43 are set according to a preset height difference. One end of the first path 41 is connected to the second path 42, and the other end of the first path 41 is connected to the third path 43, so that the first path 41 is an inclined channel.

[0059] In one embodiment, reference Figure 1 and Figure 4 At least one of the junctions between the first path 41 and the second path 42, and between the first path 41 and the third path 43, is a smooth transition. Specifically, the first path 41, the second path 42, and the third path 43 are provided with transition structures to allow the hinge shaft 54 ​​to move smoothly back and forth between the first path 41 and the third path 43. For example, an arc-shaped structure is provided at the junction between the first path 41 and the second path 42, and an arc-shaped structure is provided at the junction between the first path 41 and the third path 43. When the hinge shaft 54 ​​moves from one path to another, the arc-shaped transition structure ensures that the hinge shaft 54 ​​moves more smoothly.

[0060] In one embodiment, reference Figure 1 and Figure 4 The guide rail 4 includes a guide groove with a groove structure, which is set on the guide plate 6. The guide groove is divided into a first path 41, a second path 42, and a third path 43. The driving member 53 and the transmission member 52 are hinged to each other by a pin. The width of the guide groove is adapted to the pin, and one end of the pin is placed in the groove of the guide groove. The pin slides or rolls with the groove wall of the guide groove. The guide rail 4 is a grooved rail, which can more stably allow the hinge shaft 54 ​​to move within the guide rail 4, and the grooved rail can avoid the protrusion of the convex rail, which would increase the overall width of the slide saddle 1.

[0061] In one embodiment, reference Figure 1 and Figure 4 There are two linkage mechanisms 5, which are symmetrically arranged on both sides of the protective cover 3, and each linkage mechanism 5 is equipped with a guide rail 4. When the slide ram 2 moves, the linkage mechanisms 5 on the left and right sides of the slide saddle 1 work simultaneously.

[0062] Furthermore, in one embodiment, reference is made to... Figure 1 and Figure 5 The machine tool machining head assembly also includes a protective shell 8, which is fitted around the outer periphery of the spindle 7 to protect it. A protective cover 3 is fitted around the outer periphery of the protective shell 8. The protective shell 8 can extend or retract relative to the protective cover 3 under the drive of the spindle 7, and the protective cover 3 and the protective shell 8 slide in a seal. That is, a sealing structure is provided between the protective cover 3 and the protective shell 8, which seals the gap between them to reduce the problem of debris being brought into the slide saddle 1 when the spindle 7 retracts.

[0063] Further, refer to Figure 1 and Figure 5 The machine tool processing head assembly includes a scraper 9, which is circumferentially attached to the inner wall of the protective cover 3 and the outer wall of the protective shell 8. The scraping end of the scraper 9 acts on the outer wall of the protective shell 8.

[0064] Furthermore, in one embodiment, reference is made to... Figure 1 and Figure 5 At least two scraper blades 9 are spaced apart on the inner wall of the protective cover 3 along the extension direction of the main shaft 7, and both scraper blades 9 are inclined. With the extension direction of the main shaft 7 as the front, the at least two scraper blades 9 extend from the inner wall of the protective cover 3 and towards the outer wall of the protective shell 8 and towards the front. Specifically, the scraper blades 9 are set on the protective cover 3 and located between the protective cover 3 and the protective shell 8. The scraper blades 9 are arranged around the protective shell 8 or along the inner wall of the protective shell 8, and the scraper blades 9 are close to the protective shell 8, so that when the protective cover 3 and the protective shell 8 move relative to each other, the scraper blades 9 can clean the protective cover 3. The scraper blades 9 are inclined with the extension direction of the slide ram 2 on the lower side, which can effectively block debris on the outside (the extension direction of the slide ram 2 is the outside).

[0065] The principle of the machine tool processing head assembly of this application will be described in general using one specific scenario of the above embodiments:

[0066] refer to Figure 1 and Figure 4 A guide rail 4 is set on the slide 2. The guide rail 4 is configured to include a second path 42, a first path 41 and a third path 43 connected in sequence. The second path 42 and the third path 43 are both set horizontally. The first path 41 is set at an acute angle to the extension direction of the slide 2 (that is, it is set at an angle from the rear to the front of the extension direction of the slide 2).

[0067] The linkage mechanism 5 is configured to include a driven member 51, a transmission member 52, and a driving member 53, which are hinged sequentially. The driven member 51 is connected to the protective cover 3, and the hinge point between the driven member 51 and the transmission member 52 is linearly slidable on the slide saddle 1. The hinge point (i.e., the hinge shaft 54) between the transmission member 52 and the driving member 53 is located within the guide rail 4. The end of the driving member 53 away from the transmission member 52 is rotatably mounted on the slide saddle 1.

[0068] When the slide 2 moves in the extending direction (the hinge shaft 54 ​​is in the extended position) Figure 1 When the state shown is reached, the hinge shaft 54 ​​first moves along the second path 42 to the side away from the extension direction. At this time, the second track will not generate thrust on the driven member 51 and the transmission member 52, and the protective cover 3 is in the second state of not moving.

[0069] When the hinge shaft 54 ​​enters the first path 41, the inclined surface of the first path 41 exerts a thrust on the hinge shaft 54. The force on the hinge shaft 54 ​​pushes the hinge point of the driven member 51 and the transmission member 52 to slide along the extension direction of the slide block 2 on the second guide rail on the slide saddle 1, thereby driving the protective cover 3 to move together with the slide block 2, so that the protective cover 3 is in the first state of moving in the extension direction of the slide block 2.

[0070] When the hinge shaft 54 ​​enters the third path 43, the slide 2 continues to move towards the extension direction, allowing the hinge shaft 54 ​​to slide horizontally along the third path 43. Since the third path 43 is horizontal, it does not exert any thrust on the hinge shaft 54. At this time, the protective cover 3 remains stationary. When the hinge shaft 54 ​​enters the third path 43, the protective cover 3 has already moved to its maximum displacement in the extension direction. The slide 2 continues to extend, allowing the spindle 7 to extend further, meeting the machining requirements for the spindle 7's extension length. Furthermore, when the slide 2 moves along the extension direction (here...) Figure 1 Under the maximum displacement (left side), the protective cover 3 and the sliding saddle 1 partially overlap in the orthographic projection direction, that is, there is no gap between the protective cover 3 and the sliding saddle 1 in the orthographic projection direction, so as to prevent chips or debris from entering the sliding saddle 1 from the gap between the protective cover 3 and the sliding saddle 1, thereby protecting the sliding saddle 1.

[0071] During the extension movement of the slide 2, the transmission component 52 and the extension direction of the slide 2 always maintain an obtuse angle relationship. When the slide 2 retracts, the hinge shaft 54 ​​slides from the third path 43 to the second path 42. The principle of its motion can be referred to the process of the slide 2 extending, which will not be repeated here.

[0072] A machine tool according to a second aspect of the present invention, with reference to Figure 1 and Figure 2 The machine tool includes a machining head assembly comprising any of the above-mentioned components. The machine tool also includes a base and a column, with the column mounted on the base and the slide saddle 1 vertically mounted on the column. By installing the machining head assembly of any of the aforementioned embodiments on the machine tool, the workpiece can be machined by moving the slide saddle 2.

[0073] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A machine tool head assembly comprising a saddle (1) and a ram (2) which is slidably arranged on the saddle (1), characterized in that, Also comprising: a protective cover (3) comprising a guard plate arranged circumferentially around the slide ram (2), the protective cover (3) being arranged at the front of the slide ram (2) in the extension direction of the slide ram (2); a guide rail (4) arranged at the side of the slide ram (2), the guide rail (4) having a first path (41) arranged obliquely, the first path (41) being obliquely arranged in such a way that the height gradually increases along the extension direction of the slide ram; and a linkage mechanism (5) comprising a driving member (53), a transmission member (52) and a driven member (51) connected in sequence, one end of the driving member (53) away from the transmission member (52) being hingedly connected to the slide saddle (1), one end of the driven member (51) away from the transmission member (52) being fixedly connected to the protective cover (3), the joint at which the driving member (53) and the transmission member (52) are hingedly connected to each other being capable of sliding along the guide rail (4). In the present application, the maximum extension stroke of the protective cover (3) and the lengths of the driving member (53) and the transmission member (52) satisfy a predetermined relationship.

2. The machine tool head assembly of claim 1, wherein, The maximum extension stroke Δx of the protective cover (3) satisfies the following relationship: Δx = |(a·cosa' + b·cosβ') - (a·cosα + b·cosβ)|; In the above formula, a and b are the lengths of the driving member and the transmission member respectively, α and α' are the angles between the length direction of the driving member and the extension direction of the slide ram at the beginning and end of the extension of the protective cover (3) respectively, and β and β' are the angles between the length direction of the transmission member and the extension direction of the slide ram at the beginning and end of the extension of the protective cover (3) respectively.

3. The machine tool head assembly of claim 2, wherein, The height difference Δh between the two ends of the first path satisfies the following relationship: Δh = a·|sinα' - sinα|.

4. The machine tool head assembly of claim 2 wherein, The lengths a of the driving member and b of the transmission member are equal, and the maximum extension stroke Δx of the protective cover (3) satisfies the following relationship: Δx = 2a·|cosα' - cosα|. The ratio of the maximum extension stroke Δx of the protective cover (3) to the height difference Δh between the two ends of the first path satisfies:

5. The machine tool head assembly of claim 1, wherein, The guide rail (4) further has a second path (42) connected to the first path (41), the extension direction of the second path (42) being parallel to the sliding direction of the slide ram, and the second path (42) being located in front of or behind the first path (41) in the extension direction of the slide ram (2).

6. The machine tool head assembly of claim 5, wherein, The guide rail (4) further has a third path (43) connected to the first path (41), the extension direction of the third path (43) being parallel to the sliding direction of the slide ram, and the third path (43) being connected to different ends of the first path (41) from the second path (42) respectively.

7. The machine tool head assembly of claim 6, wherein, At least one of the connection between the first path (41) and the second path (42) and the connection between the first path (41) and the third path (43) is a smooth transition.

8. The machine tool head assembly of claim 1, wherein, The guide rail comprises a guide groove with a groove structure, the driving member (53) and the transmission member (52) are mutually hinged through a pin, the groove width of the guide groove is matched with the pin, and one end of the pin is placed in the groove of the guide groove; the pin is in sliding fit or rolling fit with the groove wall of the guide groove.

9. A machine tool head assembly according to any one of claims 1 to 8, wherein, The number of the linkage mechanisms (5) is two, and the linkage mechanisms are symmetrically arranged on two sides of the protective cover (3); and / or, The first path (41) is an arc-shaped path.

10. A machine tool, characterized by The machine tool further comprises a base and a column, the column is arranged on the base, and the slide saddle (1) is liftably installed on the column.

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