WO2021151930A1

WO2021151930A1 - Vibration control device with resilient ring retention element

Info

Publication number: WO2021151930A1
Application number: PCT/EP2021/051839
Authority: WO
Inventors: Gil Pesquera; Aurélien FRAYSSE; Xavier Vermelle
Original assignee: Vitesco Technologies GmbH
Priority date: 2020-01-31
Filing date: 2021-01-27
Publication date: 2021-08-05
Also published as: FR3106895B1; FR3106895A1

Abstract

Disclosed is a vibration control device (1) comprising: a base (7); a coupling bolt (3) comprising a threaded segment (11) and a non-threaded segment (10) that are coaxial; a contact surface (5); an open resilient retention ring (15) having, on its inner face, an inner shoulder (16), this inner shoulder (16) abutting against the junction of the threaded segment (11) and the non-threaded segment (10) of the coupling bolt (3).

Description

DESCRIPTION

Title: Vibration control device with snap ring retention element

TECHNICAL AREA

The invention relates to the technical field of mechanical vibration control. The invention relates to a vibration control device intended to be coupled to a vibrating element for, for example, detecting a certain vibratory regime of the vibrating element, measuring the frequency or amplitude of the vibrations of the vibrating element, damping the vibrations of the vibrating element.

Vibration control devices generally have a planar contact surface intended to be fixed against a planar receiving surface located on the vibrating element so that vibrations from the vibrating element are transmitted optimally, minimizing vibrational losses. , to the vibration control device. This plane-to-plane contact requires a significant compressive force of the vibration control device against the vibrating element. Vibration control devices are therefore usually attached to the vibrating element by tightening a coupling screw.

The quality of the plane-to-plane contact between the contact surface of the vibration control device and the flat receiving surface guarantees the quality of vibration transmission between the vibrating element and the device, and therefore the proper functioning of the device. The contact surface between the device and the vibrating element is thus preferably maximized.

In addition, vibration control devices are typically shipped with their coupling screws captive in the through hole to facilitate assembly line manufacturing. Placing the vibration control device against the vibrating element for which it is intended results in the positioning of the coupling screw without any additional step. No operation of fitting the coupling screw in the through hole is thus necessary and the operation is secured by the impossibility of losing the coupling screw.

PRIOR ART There are known vibration control devices comprising a captive coupling screw in their through orifice. For example, document FR3047801 describes a knocking sensor comprising a coupling screw mounted in the through hole by a centering spacer cooperating with a retaining ring mounted on the coupling screw.

Solutions are also known which propose coating a portion of the thread of the coupling screw with an elastic material forming an annular stop against the contact surface, preventing removal of the coupling screw from the through hole. It is also known to form such an annular stop by an O-ring tightened on the coupling screw and coming into abutment on the contact surface.

Prior art solutions provide retention of the coupling screw in the through-bore but do not allow precise positioning of the screw end at the contact surface. In addition, the known solutions generally use a retention element which, when the vibration control device is clamped on the vibrating element, interferes with the junction of the two flat surfaces in contact. It is then necessary to provide a receiving counterbore for such retention elements so as not to disturb the plane-to-plane contact, which complicates the production of the contact surfaces and which further reduces the useful contact surface.

STATEMENT OF THE INVENTION

The invention aims to improve the vibration control device of the prior art.

To this end, the invention relates to a vibration control device comprising:

- a base pierced with a through hole which extends along a fixing axis;

- a coupling screw arranged in the through hole extending along the fixing axis;

- means for retaining the coupling screw in the through hole;

- A flat contact surface suitable for a plane-on-plane connection with a vibrating element, this contact surface extending in a plane perpendicular to the fixing axis while being disposed around the through hole.

In this device: - the coupling screw comprises a threaded section and a coaxial non-threaded section;

- The retention means comprise an open elastic retention ring having, on its internal face, an internal shoulder, this internal shoulder being in abutment against the junction of the threaded section and the non-threaded section of the coupling screw.

Such a vibration control device benefits from a retention element which retracts into the internal surface of the through-hole so that this retention element can in no way disturb the junction of the flat surfaces. No counterboring or special housing is necessary to retract the elastic retention ring of the device.

In addition, the retention element of the device according to the invention allows the coupling screw to be maintained in a position chosen for mounting of the device. The vibration control device can thus for example be delivered with its coupling screw, the end of which is flush with the plane of the contact surface. The assembly of the device is then facilitated and accelerated because it suffices to position the device against the vibrating element, the end of the coupling screw being positioned opposite a threaded bore provided on the vibrating element, and the assembly is finalized by a single operation of tightening the coupling screw. No further manipulation or positioning of the coupling screw is necessary.

In addition to this optimal positioning during assembly, the retention element ensures that the coupling screw is captive, which cannot be accidentally removed from the device during, for example, transport and handling of the device.

Furthermore, the retention element of the device allows adjustment of the relative position of the coupling screw with respect to the through-bore because it is possible to slide the coupling screw along the fixing axis until 'at a chosen position where it will be maintained by the retention element.

The vibration control device thus has a captive coupling screw, the position of which is maintained optimally and is also adjustable, maximizing the contact surface between the contact surface of the device and the receiving surface of the device. vibrating element. These functions are achieved by means of an inexpensive and easy to manufacture retention element. According to another object, the invention relates to a method of mounting a vibration control device as described above on a vibrating element comprising a flat receiving surface, this method comprising the following steps:

a step of bringing the contact surface of the device into contact plane on plane against the receiving surface of the vibrating element, the coupling screw being opposite a threaded bore of the vibrating element ;

- a first step of screwing the coupling screw into the tapped bore, step in which the elastic retention ring is driven with the coupling screw along the fixing axis while sliding against the internal wall of the through orifice, until it comes into contact with the flat receiving surface of the vibrating element;

- a second step of screwing the coupling screw into the tapped bore, step in which the elastic retention ring is held in the through hole, against the flat receiving surface of the vibrating element, the screw d 'coupling moving relative to the elastic retention ring along the fixing axis.

The device according to the invention may have the following additional characteristics, alone or in combination:

- the internal shoulder of the elastic retention ring rests against the first thread of the threaded section of the coupling screw;

- the elastic retention ring comprises a clamping ring extending from the internal shoulder, along the fixing axis, and in the direction of the contact surface, this clamping ring clamping the threaded section of the screw coupling and being disposed against the internal wall of the through orifice;

- the clamping ring is mounted tight between the threaded section and the internal wall of the through hole;

- the through hole has a guide bore for the elastic retention ring, this guide bore being delimited by a shoulder forming an axial stop for the elastic retention ring;

- the elastic retention ring has an elastic lip abutting against the shoulder of the guide bore;

- the distance between the shoulder of the guide bore and the contact surface is substantially equal to the length of the threaded section of the coupling screw;

- The internal shoulder of the elastic retention ring is formed by an internal collar arranged vis-à-vis an external groove of the elastic retention ring; - the base is mechanically coupled to an accelerometer sensor.

The invention also relates to any internal combustion engine or any motor vehicle comprising the device according to any of the characteristics listed above.

PRESENTATION OF FIGURES

Other characteristics and advantages of the invention will emerge from the non-limiting description which follows, with reference to the accompanying drawings in which:

[Fig. 1]: Fig. 1 is a sectional view showing a vibration control device positioned against a vibrating element;

[Fig. 2]: Figure 2 shows in perspective the coupling screw of the device of Figure 1;

[Fig. 3]: Figure 3 illustrates the device of Figure 1 with the coupling screw screwed into a threaded bore of the vibrating element;

[Fig. 4]: Figure 4 illustrates a step of mounting the coupling screw in the device of Figure 1.

DETAILED DESCRIPTION

Figure 1 is a sectional view showing a vibration control device positioned on a vibrating element 2. The device 1 comprises a coupling screw 3 ready to be screwed into a threaded bore 6 of the vibrating element 2.

In the present example, the vibration control device 1 is an automotive knock sensor and the vibrating element 2 is a part of the engine block of an internal combustion engine motor vehicle.

The vibrating element 2 has a flat receiving surface 4 for the device 1. The device 1 also comprises a flat contact surface 5 adapted to come into contact with the receiving surface 4.

The device 1 comprises a base 7 which is mechanically coupled, in the present example aimed at a knocking sensor, to an accelerometer sensor 8.

The screw 3 has a head 9 and a body consisting of an unthreaded section 10 (a smooth rod), and a threaded section 11. At the junction between the non-threaded section 10 and the threaded section 11, the thread of the screw 3 protrudes from the non-threaded surface and thus forms a shoulder.

The screw extends along an axis 12 called "fixing axis". The unthreaded 10 and threaded 11 sections are coaxial and extend along this fixing axis 12.

The base 7 comprises a through hole 13 extending along the fixing axis 12. The portion of the through hole 13 which opens onto the contact surface 5 comprises a guide bore 14 which locally increases the diameter of the through orifice 13 and which forms a shoulder 22.

Referring to Figures 1 and 2, the latter showing the screw 3 in perspective, the device 1 is provided with a retention element which here comprises an elastic ring 15 for retention. The elastic ring 15 has on its internal face an internal shoulder 16. In the present example, the elastic ring 15 is an annular part made of an elastically deformable polymer such as polypropylene. The elastic ring comprises a clamping ring 17, the diameter of which is adapted to grip the threaded section 11 of the screw 3. The elastic ring 15 further comprises a groove 18 which forms on the internal surface of the elastic ring 15 a collar 19 which locally restricts the diameter of the elastic ring 15. The shoulder 16 is located on the internal surface of the ring 15, at the junction between the clamping ring 17 and the collar 19.

The elastic ring 15 is open because it comprises, in the present example, a cutout 20. The elastic ring 15 further comprises an elastic lip 21 disposed on the edges of the groove 18.

The diameter of the elastic ring 15 is chosen so that the first section 17 has an internal diameter smaller than the external diameter of the threaded section 11 so that, thanks to the cutout 20 of the elastic ring 15, the elastic behavior of the 'ring 15 allows the tightening of the threaded section 11 by the first section 17 of the elastic ring 15.

Furthermore, the thickness of the elastic ring 15 is chosen so that, in the position of FIG. 1, the outer diameter of the elastic ring 15 is fitted in the guide bore 14 with a slight tightening so that 'a sliding of the ring elastic 15 in the guide bore 14 is possible by exerting a voluntary force on the screw 3.

In the position of Figure 1, the coupling screw 3 is mounted in the device 1 so that the elastic lip 21 comes into contact with the shoulder 22. The dimensions of the guide bore 14, of the ring elastic 15, and of the threaded section 11 of the screw 3 are chosen so that, in this position of FIG. 1, the end of the screw 3 is flush with the level of the plane in which the contact surface 5 extends. between the shoulder 22 and the contact surface 5 is thus substantially equal to the length of the threaded section 11, so that the height of the portion of the elastic ring 15 which is between the internal shoulder 16 and the top causes the 'chamfered end of screw 3 to protrude slightly from the plane in which the contact surface extends (see Figure 1). This chamfered end of the screw 3 is thus engaged at the entry of the threaded bore 6 when the device 1 is positioned against the vibrating element.

This arrangement allows the positioning of the device 1 on the vibrating element 2 by directly obtaining the plane-to-plane contact of the contact surface 5 on the receiving surface 4 without the coupling screw 3 hindering this positioning. . The screw 3 is however directly put into position without specific operation vis-à-vis the threaded bore 6, and ready for screwing.

Before mounting the device 1 on the vibrating element 2, the elastic ring 15 has provided retention of the screw 3 in the through-hole 13, ensuring both the captive nature of the screw 3 and its retention in a position optimal mounting.

Furthermore, the operator or the machine in charge of mounting the device 1 on the vibrating element 2 can manually adjust the position of the screw 3 along the fixing axis 12 by acting on the head of the screw 3 in the direction of the fixing axis 12, which causes a displacement of the screw 3 which brings with it the elastic ring 15, the latter sliding against the guide bore 14. The elastic ring 15 is thus also suitable for maintain in position the screw 3 in the through hole 13 in other desired positions along the fixing axis 12.

The preferred position illustrated in FIG. 1 can furthermore be obtained again by moving the head of the screw 3 of the device 1 away until the elastic lip 21 abuts against the shoulder 22. The elastic lip 21 provides a amortization of the stop longitudinal of the screw 3 with respect to the through hole 13. In addition, when positioning the device 1 on the vibrating element 2, the elastic lip 21 offers a degree of freedom in translation along the axis fixing 12 for screw 3, useful for example for positioning screw 3 at the entry of threaded bore 6.

The elastic ring 15 has an external annular friction surface 23 intended to hold by friction, against the guide bore 14, the screw 3.

Once the device 1 is in place as shown in FIG. 1, only one assembly operation of the device 1 is necessary and consists in screwing the screw 3 until the head of the screw 3 tightens the base 7 to the desired torque against the vibrating element 2. FIG. 3, which is a half-section, represents the assembly obtained following this screwing operation.

The screwing operation is carried out in two stages. In a first step, the elastic ring 15 remains in position against the threaded section 11 of the screw 3 while it is driven by a relative downward movement with respect to the guide bore 14 and thus scrapes the surface. internal bore 14. This movement continues until the clamping ring 17 comes into contact with the receiving surface 4 of the vibrating element 2. The screwing of the screw 3 then continues in a second step where the elastic ring 15 remains in this position against the surface 4. A relative movement along a helical connection is then implemented between the threaded section 11 and the internal surface of the clamping ring 17.

The half-section of FIG. 4 illustrates the mounting of the elastic ring 15 on the screw 3. The screw 3 is first of all placed in the through-hole 3 of the device 1 and the elastic ring 15 is then placed. arranged around the threaded section 11 so that its internal shoulder 16 comes to rest against the first thread of the threaded section 11. The positioning of the elastic ring 15 is made possible by the elastic properties of the ring and its open nature. From the position of Figure 4, the head 9 of the screw 3 is then moved away from the base 7 until the elastic lip 21 comes into contact with the shoulder 22 of the guide bore 14.

To ensure this assembly, the length of the non-threaded section 10 is chosen so that, when the head 9 of the screw 3 is in contact with the device 1 (position of FIG. 4), the junction between the non-threaded section 10 and the section threaded 11 protrudes outside the through-hole 13, to allow the mounting of the elastic ring 15.

Alternative embodiments of the vibration control device can be implemented without departing from the scope of the invention. The device can in fact be any device requiring the transmission of vibrations from a vibrating element by a plane-to-plane contact, such as sensors relating to the analysis of vibratory behavior, vibration absorbers or dampers, etc.

Furthermore, the elastic ring 15 may have other shapes while retaining its open character and its internal shoulder 16, for example a continuous cylindrical outer shape and an internal shoulder 16 formed of an annular rib.

Claims

1. Vibration control device (1) comprising:

- a base (7) pierced with a through hole (13) which extends along a fixing axis (12);

- a coupling screw (3) arranged in the through hole (13) extending along the fixing axis (12);

- means for retaining the coupling screw (3) in the through hole (13);

- a planar contact surface (5) suitable for a plane-on-plane connection with a vibrating element, this contact surface (5) extending in a plane perpendicular to the fixing axis (13) being disposed around the 'through orifice (13);

- the coupling screw (13) comprising a threaded section (11) and an unthreaded section (10) coaxial;

- the retention means comprising an open elastic retention ring (15) having, on its internal face, an internal shoulder (16), this internal shoulder (16) being in abutment against the junction of the threaded section (11) and of the section thread (10) of the coupling screw (3), said device being characterized in that the through hole (13) has a guide bore (14) of the elastic retention ring (15), this bore guide (14) being delimited by a shoulder (22) forming an axial stop for the elastic retention ring (15).

2. Device according to claim 1, characterized in that the internal shoulder (16) of the elastic retention ring (15) rests against the first thread of the threaded section (11) of the coupling screw (3).

3. Device according to any one of the preceding claims, characterized in that the elastic retention ring (15) comprises a clamping ring (17) extending from the internal shoulder (16), according to the fixing axis (12), and in the direction of the contact surface (5), this clamping ring (17) enclosing the threaded section (11) of the coupling screw (3) and being disposed against the internal wall of the through hole (13).

4. Device according to claim 3, characterized in that the clamping ring (17) is mounted clamped between the threaded section (11) and the internal wall of the through hole (13).

5. Device according to claim 1, characterized in that the elastic retention ring (15) comprises an elastic lip (21) abutting against the shoulder (22) of the guide bore (14).

6. Device according to one of claims 1 or 5, characterized in that the distance between the shoulder (22) of the guide bore (14) and the contact surface (5) is substantially equal to the length of the threaded section (11) of the coupling screw (3).

7. Device according to any one of the preceding claims, characterized in that the internal shoulder (16) of the elastic retention ring (15) is formed by an internal collar (19) disposed vis-à-vis d 'an outer groove (18) of the elastic retention ring (15).

8. Device according to any one of the preceding claims, characterized in that the base is mechanically coupled to an accelerometer sensor (8).

9. A method of mounting a vibration control device (1) according to one of claims 1 to 8 on a vibrating element (2) comprising a flat receiving surface (4), characterized in that it comprises the following steps :

- a step of bringing the contact surface (5) of the device (1) into contact plane on plane against the receiving surface (4) of the vibrating element (2), the coupling screw (3) being in vis-à-vis a threaded bore (6) of the vibrating element (2);

- a first step of screwing the coupling screw (3) in the threaded bore (6), step in which the elastic retention ring (15) is driven with the coupling screw (3) according to the fixing pin (12) by sliding against the internal wall of the through-hole (13), until it comes into contact with the flat receiving surface (4) of the vibrating element (2);

- a second step of screwing the coupling screw (3) into the threaded bore (6), step in which the elastic retention ring (15) is held in the through hole (13), against the surface receiving plane (4) of the vibrating element (2), the coupling screw (3) moving relative to the elastic retention ring (15) along the fixing axis (12).

10. Internal combustion engine characterized in that it comprises a device according to any one of claims 1 to 8.

11. Motor vehicle characterized in that it comprises a device according to any one of claims 1 to 8.