Switching assembly having auxiliary body for setting switching point

Abstract

The invention relates to a switching assembly comprising a base body in which a tappet is received in a linearly movable manner in the direction of a longitudinal axis, a switching device is provided, which can be actuated by means of the tappet, the switching device comprising a first external thread, which is arranged concentrically to the longitudinal axis, and a second external thread, which is arranged concentrically to the longitudinal axis. The first external thread is screwed into the first internal thread, and an independent locking nut is arranged in the first external thread. According to the invention, a separate auxiliary body is provided, the first internal thread is arranged on the auxiliary body, the first external thread is screwed into the first internal thread in such a way that the switching device can be tensioned with the auxiliary body, the auxiliary body has a second external thread and a third external thread, each of which is arranged concentrically to the longitudinal axis, wherein the second external thread is screwed into the second internal thread on the base body, the locking nut is screwed onto the third external thread, the locking nut can be tensioned relative to the base body, and the auxiliary body is sealed relative to the base body.

Description

Technical Field

[0001] The present invention relates to a switching structure assembly according to the preamble of claim 1. Background Technology

[0002] A switching mechanism assembly is known from DE 10 2018 201 937 A1. The switching device of this assembly is operated by a push rod that can move along a longitudinal axis. The switching mechanism assembly has a first external thread that screws into a first internal thread at the base of the assembly. The switching point of the assembly is set by means of this threaded connection, and this setting is locked by means of a lock nut. It is possible that liquid can enter the interior of the switching mechanism assembly from the surrounding environment through these two threaded connections—that is, through the threaded connection between the lock nut and the first base, and the threaded connection between the first external thread and the first internal thread. There, although the incoming moisture should be sealed by an O-ring stack, it has been shown that moisture can still pass through the O-ring stack until it reaches the switching device, causing the switching device to malfunction due to the ingress of moisture. This problem is particularly problematic when the O-ring stack is incorrectly assembled, where proper assembly is difficult to detect. Summary of the Invention

[0003] The purpose of this invention is to improve the sealing of the switching structure assembly relative to liquids entering from the outside.

[0004] According to the independent claim, a separate auxiliary body is provided, wherein a first internal thread is arranged at the auxiliary body, wherein a first external thread is screwed into the first internal thread such that the switching device can be tensioned with the auxiliary body, wherein the auxiliary body has a second external thread and a third external thread, which are respectively arranged concentrically with the longitudinal axis, wherein the second external thread is screwed into the second internal thread at the base, wherein a locking nut is screwed onto the third external thread, wherein the locking nut can be tensioned relative to the base, and wherein the auxiliary body is sealed relative to the base.

[0005] Therefore, the threaded connection between the first external thread and the first internal thread no longer moves after the initial assembly. This allows for a seamless seal of the threaded connection. It is conceivable that hemp or PTFE tape could be used for this purpose, with the first sealing ring, explained further below, being preferred. Sealing of the threaded connection at the locking nut, i.e., at the third external thread, is no longer critical. Instead, the large auxiliary body can be sealed relative to the base material without problems. For this purpose, the second sealing ring, explained further below, is preferred. However, a gap seal is also conceivable as an alternative, wherein the auxiliary body is precisely fitted to the base material, and the corresponding sealing surface is preferably cylindrical about the longitudinal axis.

[0006] Preferably, the switching device is tensioned directly relative to the auxiliary body, especially without an additional locking nut. Preferably, the locking nut is tensioned relative to the base body.

[0007] Advantageous modifications and improvements of the invention are indicated in the dependent claims.

[0008] A first sealing ring can be provided, which surrounds the longitudinal axis, and is installed between the auxiliary body and the switching device in the orifice region of the first internal thread. The corresponding sealing portion can be implemented completely and without problems. The first sealing ring is preferably constructed in the form of an O-ring.

[0009] The first sealing ring can be installed between the auxiliary body and the switching device along the longitudinal axis such that it can be compressed by screwing the first external thread into the first internal thread. This preload improves the seal. Preferably, the first sealing ring is compressed by screwing the first external thread into the first internal thread. Preferably, the desired preload is achieved when the switching device, excluding the first sealing ring, directly abuts against the auxiliary body.

[0010] A second sealing ring can be provided, which surrounds the longitudinal axis and is arranged between the second and third external threads along the longitudinal axis. The second sealing ring preferably abuts against the base and the auxiliary body in a sealing manner. This enables a sealing portion that remains sealed even after adjusting the switching point.

[0011] It can be configured such that the second sealing ring is arranged radially relative to the longitudinal axis between the auxiliary body and the base body. Therefore, the adjustment of the switching point is not significantly hindered by the second sealing ring.

[0012] The auxiliary body can be configured to have a first sealing surface, which is cylindrical about the longitudinal axis and arranged between the second and third external threads along the longitudinal axis. The base body has a second sealing surface, which is also cylindrical about the longitudinal axis and surrounds the first sealing surface. A second sealing ring is installed between the first and second sealing surfaces, and this second sealing ring seals against both surfaces. Thus, the adjustment of the switching point is almost entirely unimpeded by the second sealing ring.

[0013] It can be configured such that the diameters of the first and second sealing surfaces are matched to the second sealing ring in such a way that the second sealing ring is installed between the first and second sealing surfaces under pre-tightening. This pre-tightening improves the sealing effect of the second sealing ring.

[0014] It can be configured such that the diameter of the first sealing surface is smaller than the root diameter of the second external thread and smaller than the root diameter of the third external thread. This simplifies the manufacturing of the second and third external threads because the area of ​​the first sealing surface functions as a relief groove at the end of the aforementioned external thread. For example, the final machining of the first sealing surface by turning can be performed before manufacturing the two aforementioned external threads without damaging the first sealing surface.

[0015] It can be configured such that the outer diameter of the third external thread is between 90% and 110% of the outer diameter of the second external thread. Preferably, the outer diameters of the second and third external threads are identical. This results in a significantly reduced structural space required for switching structural components.

[0016] It can be configured such that the auxiliary body is perforated along the longitudinal axis, and a push rod passes through the perforation so that the push rod can operate the switching device. The perforation can have an internal hexagonal structure, wherein the auxiliary body, when using the internal hexagonal structure, can be tensioned, preferably tensioned, with the switching device.

[0017] It can be configured that the second external thread and the corresponding second internal thread are fine threads. This allows for particularly precise setting of the switching point of the switching device. Fine threads are, for example, objects of standard DIN 13-2. The first external thread and / or the third external thread are preferably implemented as ordinary threads. Ordinary threads are, for example, objects of standard ISO 261.

[0018] It can be configured that the helix direction of the first external thread and the helix direction of the third external thread are opposite. This prevents the switching device from loosening when the lock nut is tightened. The third external thread is preferably constructed as a left-hand thread, while the first external thread is preferably constructed as a right-hand thread.

[0019] Of course, the features mentioned above and those to be explained below can be used not only in their respective combinations, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description

[0020] The invention will now be explained in detail with reference to the accompanying drawings. Wherein: Figure 1 A longitudinal sectional view of a switching structure assembly according to the invention is shown, which is assembled at a higher-level structure assembly. Detailed Implementation

[0021] Figure 1A longitudinal sectional view of a switching structure assembly 10 according to the invention is shown, which is mounted on a higher-level structure assembly 70. The cutting plane coincides with the longitudinal axis 11. The higher-level structure assembly 70 can be an axial piston machine or other hydraulic press. The switching device 12 includes, for example, an electric switch that is operated when the displacement volume of the axial piston machine is set to zero. A corresponding adjustment movement, such as the movement of a pivoting rocker arm of the axial piston machine in a swashplate configuration, is transmitted to the switching device 12 by means of a push rod 22 movable in the direction of the longitudinal axis 11. The switching device 12 can be a mechanical switch, wherein a contactless switch, such as a proximity switch, can also be used.

[0022] In order to set the switching point, the position of the switching device 12 along the longitudinal axis 11 can be adjusted in the direction of the longitudinal axis 11 by means of the thread engagement between the second external thread 32 and the second internal thread 42. The corresponding setting is locked by means of the locking nut 23. The second external thread 32 is preferably constructed as a fine thread so as to achieve precise setting of the switching point of the switching device 12. The third external thread 33 is preferably implemented as a left-hand thread, wherein the first external thread 31 is implemented as a right-hand thread. Thus, the switching device 12 will not loosen when the locking nut 23 is tightened.

[0023] A second internal thread 42 is disposed at the base 20 of the switching structure assembly 10, wherein the base 20 is fastened, for example, threadedly connected to the upper-level structure assembly 70. A second external thread 32 is disposed at a separate auxiliary body 21. The switching device 12 is threadedly connected to the auxiliary body 21, wherein the switching device 12 has a first external thread 31 that screws into the first internal thread 41 of the auxiliary body 21. A locking nut 23 is screwed onto the third external thread 33 of the auxiliary body 21, wherein the locking nut is tensioned relative to the base 20.

[0024] The auxiliary body 21 is penetrated by a through hole 24 along the longitudinal axis 11, the through hole leading to the first internal thread 41. The through hole 24 is penetrated by a push rod 22, which can operate the switching device 12. The through hole 24 is provided with an internal hexagonal structure, so that an internal hexagonal wrench can be applied there to tension the auxiliary body 21 relative to the switching device 12.

[0025] The switching structure assembly 10 is sealed to prevent liquid from entering from the outside. Simultaneously, this seal design prevents liquid from the interior of the upper structure assembly 70 from leaking into the surrounding environment through the switching structure assembly 10. It should be noted that the internal space of the axial piston machine is filled with hydraulic fluid, which is typically at a pressure slightly higher than the ambient air pressure.

[0026] After the initial assembly, no further movement occurs between the auxiliary body 21 and the switching structure assembly 10. The preferred configuration there is a first sealing ring 61 of an O-ring surrounding the longitudinal axis 11. This first sealing ring is arranged in the orifice region of the first internal thread 41, wherein the first sealing ring is pre-tightened between the auxiliary body 21 and the switching device 12 along the longitudinal axis 11. The pre-tightening is achieved by screwing the first external thread 31 into the first internal thread 41. The desired pre-tightening is achieved when the switching device 12, except for the first sealing ring 61, directly abuts against the auxiliary body 21.

[0027] A second sealing ring 62 is arranged between the base 20 and the auxiliary body 21. Because movement occurs to set the switching point during this sealing engagement, the sealing concept of the first sealing ring 61 cannot be used here. The second sealing ring 62 surrounds the longitudinal axis 11, and is preferably constructed as an O-ring. The second sealing ring abuts radially inward against a first sealing surface 51 on the auxiliary body 21, which is cylindrical about the longitudinal axis 11. The second sealing ring 62 abuts radially outward against a second sealing surface 52 on the base 20, which is also cylindrical about the longitudinal axis 11.

[0028] A first sealing surface 51 is arranged along the longitudinal axis 11 between the second external thread and the third external thread 32; 33. The diameter of the first sealing surface is configured to be smaller than the root diameter of the second external thread 32 and smaller than the root diameter of the third external thread 33. The outer diameter of the second external thread 32 is preferably configured to be the same as the outer diameter of the third external thread 33.

[0029] Also noteworthy is a separate guide insert 71, which guides the push rod 22 along the longitudinal axis 11. The guide insert 71 is fixedly mounted in the base 20 such that the push rod is guided at least indirectly at the base 20.

[0030] Figure label: 10. Switching structural components 11. Vertical axis 12 Switching device 20 matrix 21 Supporting bodies 22 Putter 23 Locking nut 24 piercings 31 First external thread 32 Second external thread 33 Third external thread 41 First internal thread 42 Second internal thread 51 First sealing surface 52 Second sealing surface 61 First sealing ring 62 Second sealing ring 70. Upper-level structural components 71. Guide Insert

Claims

1. A switching structure assembly (10) having a base (20) in which a push rod (22) is received in the base in a manner that allows linear movement along a longitudinal axis (11), wherein, A switching device (12) is provided, which can be operated by means of the push rod (22), wherein the switching device (12) has a first external thread (31) arranged concentrically with the longitudinal axis (11) and the first external thread is screwed into a first internal thread (41), wherein a separate locking nut (23) is provided. The device is characterized by having a separate auxiliary body (21), wherein the first internal thread (41) is arranged at the auxiliary body (21), wherein the first external thread (31) is screwed into the first internal thread (41) such that the switching device (12) can be tensioned with the auxiliary body (21), wherein the auxiliary body (21) has a second external thread and a third external thread (32; 33), which are arranged concentrically with the longitudinal axis (11), wherein the second external thread (32) is screwed into the second internal thread (42) at the base (20), wherein the locking nut (23) is screwed onto the third external thread (33), wherein the locking nut can be tensioned relative to the base (20), wherein the auxiliary body (21) is sealed relative to the base (20).

2. The switching structure component (10) according to claim 1. in, A first sealing ring (61) is provided, which surrounds the longitudinal axis (11), wherein the first sealing ring is installed between the auxiliary body (21) and the switching device (12) in the orifice region of the first internal thread (41).

3. The switching structure component (10) according to claim 2. in, The first sealing ring (61) is mounted between the auxiliary body (21) and the switching device (12) along the longitudinal axis (11) such that the first sealing ring can be compressed by screwing the first external thread (31) into the first internal thread (41).

4. The switching structure component (10) according to any one of the preceding claims. in, A second sealing ring (62) is provided, which surrounds the longitudinal axis (11) and is arranged between the second external thread and the third external thread (32; 33) along the longitudinal axis (11).

5. The switching structure component (10) according to claim 4. in, The second sealing ring (61) is arranged radially relative to the longitudinal axis (11) between the auxiliary body (21) and the base body (20).

6. The switching structure component (10) according to claim 4 or 5. in, The auxiliary body (21) has a first sealing surface (51) which is cylindrical about the longitudinal axis (11), wherein the first sealing surface (51) is arranged between the second external thread and the third external thread (32; 33) along the longitudinal axis (11), wherein the base (20) has a second sealing surface (52) which is cylindrical about the longitudinal axis (11) and surrounds the first sealing surface (51), wherein the second sealing ring (62) is installed between the first sealing surface and the second sealing surface (51; 52), wherein the second sealing ring sealably contacts the first sealing surface and the second sealing surface (52; 52).

7. The switching structure component (10) according to claim 6. in, The diameters of the first sealing surface (51) and the second sealing surface (52) are matched with the second sealing ring (62) in such a way that the second sealing ring (62) is installed between the first sealing surface and the second sealing surface (51; 52) under pre-tightening.

8. The switching structure component (10) according to any one of claims 6 or 7. in, The diameter of the first sealing surface (51) is smaller than the root diameter of the second external thread (32) and smaller than the root diameter of the third external thread (33).

9. The switching structure component (10) according to any one of the preceding claims. in, The outer diameter of the third external thread (33) is between 90% and 110% of the outer diameter of the second external thread.

10. The switching structure component (10) according to any one of the preceding claims. in, The auxiliary body (21) is penetrated by a perforation (24) along the longitudinal axis (11), wherein the push rod (22) passes through the perforation (24) so ​​that the push rod can operate the switching device (12).

11. The switching structure component (10) according to any one of the preceding claims. in, The second external thread (32) and the corresponding second internal thread (42) are constructed as fine threads.

12. The switching structure component (10) according to any one of the preceding claims. in, The helical direction of the first external thread (31) is selected in opposite directions to the helical direction of the third external thread (33).

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