FR3015027A1 - DEVICE FOR MEASURING LIQUID LEVEL - Google Patents

Abstract

The present invention relates to a liquid level measuring device comprising a body (2) and a connector (3) connected by a mechanical connection, characterized in that the body (2) and the connector (3, 6) are made of plastic and in that the mechanical connection is a laser-plastic (L) laser weld. The invention also relates to the method of producing such a device, as well as the use of this device for measuring the oil level in a crankcase.

Description

The present invention relates to the field of fluid level measuring devices, and more particularly to a device for measuring the liquid level of a vehicle, and for example a motor vehicle. It is already known liquid level measuring systems, such as for example the oil level measuring probes. These devices are conventionally formed by a connector, interface means, for example with a reservoir, and a portion called dip tube which will be in contact with the liquid whose level is to be measured. Currently, the interface means comprise a threaded portion and a gripping portion for screwing the nut-type device, and are made of metal. This metal gripping part is used to perform the crimping on the connector, which allows the mechanical maintenance of the part.

One of the disadvantages of these devices already known is that their mass is important due to the presence of metal, which also generates significant costs in terms of manufacturing. The present invention therefore aims to overcome one or more of the disadvantages of the devices of the prior art by providing a liquid level measurement device lighter than those of the prior art and less expensive. For this purpose, the present invention proposes a liquid level measuring device comprising a body and a connector connected by a mechanical connection, the body and the connector being made of plastic and the mechanical connection being a plastic-plastic laser weld.

According to one embodiment of the invention, the device comprises a gripping element. According to one embodiment of the invention, the gripping element comprises at least three faces. According to one embodiment of the invention, the device comprises a threaded portion.

According to one embodiment of the invention, the threaded portion and the gripping element are overmolded. The present invention also relates to a method of connection between a body and a device connector according to the invention, comprising a step during which the connector is held in pressure on the body of the device, and the body-connector assembly is set rotating so as to achieve a radially welded. The present invention also relates to the use of the liquid level measuring device according to the invention for measuring the oil level in a crankcase.

Other objects, features and advantages of the invention will be better understood and will appear more clearly on reading the description given hereinafter with reference to the appended figures given by way of example and in which: Figure 1 is a schematic representation of a perspective view of a device according to the invention; - Figure 2 is a schematic representation of a profile view of a device according to the invention, with the connection made. The present invention relates to a liquid level measuring device. The operation of such a probe is such that, for example, that of the probe described in the patent application FR2950968. According to one embodiment of the invention, the liquid is oil. According to one embodiment of the invention the level measuring device is an oil level sensor for a motor vehicle. As is illustrated in Figures 1 and 2, the device 1 for measuring the liquid level according to the invention is formed by a body 2 for connector 3, 3 'and a connector 3, 3'. According to one embodiment, the device comprises interface means 5, 6 and a plunger tube 4. By plunger tube 4 is meant the part that will be immersed in the liquid whose level is measured.

By means of interface 5, 6 is meant means that are in contact with elements that do not belong to the device itself. More specifically, the interface means 5, 6, illustrated in FIG. 2, comprise a threaded portion (not shown) or a non-threaded portion 5 and a gripping element 6 for screwing the device, in which a grip is arranged. a connector. In the context of the invention this gripping element 6 is plastic. When the threaded portion is present, it allows the assembly of the device 1 on a support not shown. This support is for example a wall of a crankcase. According to one embodiment of the invention, the device 1 also comprises an elongated and smooth portion, not shown, disposed between the threaded portion and the gripping member 6. This part serves to prevent the direct contact of the element of gripping with the support on which is screwed the device. According to one embodiment, the gripping element 6 has the shape of a nut and comprises at least three faces. Preferably, the gripping element 6 has six faces. According to one embodiment, the threaded portion and the gripping element 6 are overmolded. According to one embodiment of the invention, the threaded portion is made of metal and the gripping member 6 are made of plastic.

The connector 3, 3 'and the body 2 of the device 1 are made of plastics and are connected by a mechanical connection 7. In the context of the invention, the mechanical connection 7 between the body 2 and the connector 3, 3' is made by laser welding. The two elements to be bonded being plastic, the weld is a plastic / plastic laser weld.

In order to achieve the weld, the connector 3, 3 'is held in pressure on the body 2 of the device 1, and the body-connector assembly is rotated so as to perform the weld L radially. The connector 3, 3 'and the body 2 of the sensor are thus rigidly connected by the weld L.

The use of plastic elements bonded by laser welding, allows a mass gain of the device of between 15 and 50%, and preferably of at least 30% compared with the use of an element of metal grip. Such a device according to the invention also reduces the cost of the metal part because the machining is done on a metal bar of smaller size, while maintaining the robustness to the tightening torque. Such a connection makes it possible to keep a wide choice of connectors. Indeed, it suffices that the connector 3, 3 'is made of plastic so that it can be welded to the body 2 of the device 1.

The scope of the present invention is not limited to the details given above and allows embodiments in many other specific forms without departing from the scope of the invention. Therefore, the present embodiments should be considered by way of illustration, and may be modified without departing from the scope defined by the claims.

Claims (7)

REVENDICATIONS1. Liquid level measuring device (1) comprising a body (2) and a connector (3, 3 ') connected by a mechanical connection (7), characterized in that the body (2) and the connector (3, 3 ') are plastic and in that the mechanical connection is a plastic-plastic laser weld (L). 2. Device according to claim 1, comprising a gripping element (6). 3. Device according to one of claims 1 to 2, wherein the gripping element (6) comprises at least three sides. 4. Device according to one of claims 1 to 3, comprising a threaded portion. 5. Device according to one of claims 1 to 4, wherein the threaded portion and the gripping member (6) are overmolded. 6. A method of connection between a body (2) and a connector (3, 3 ') of device (1) according to one of claims 1 to 5 comprising a step during which the connector (3, 3') is maintained in pressure on the body (2) of the device (1, and the body-connector assembly is rotated so as to achieve a radially welded. 7. Use of the liquid level measuring device (1) according to one of claims 1 to 5 for measuring the oil level in a crankcase.