DE202021103686U1 - sensor housing - Google Patents

Abstract

Sensor housing (1) with at least one optical element (2),
characterized in that
Fixing means (3) are arranged between the optical element (2) and the sensor housing (1),
wherein the fixing agent (3) has swelling agent (4), wherein a swelling process of the swelling agent (4) starts with a time delay and is effective and/or can be activated, whereby the optical element (2) is pressed against the sensor housing (1), whereby the optical Element (2) is fixed.

Description

The present invention relates to a sensor housing with an optical element according to the preamble of claim 1.

When assembling optoelectronic light grid modules, light grids of different lengths are assembled using a certain number of light grid modules. The light grid modules are pushed into the sensor housing of the light grid. There are at least two conflicting requirements in the sensor housing of the light grid.

The light grid modules should be pushed into the sensor housing as easily and with as little friction as possible. With just a few modules, this is not a problem. The more modules and the longer the light grid, the more important it is that the frictional forces of the individual modules in the sensor housing do not exceed the maximum permissible insertion force on the last module that is still sticking out of the profile.

In the worst case, the modules in the sensor housing jam so tightly that the last module experiences such a high insertion force that it is damaged or, for example, optical properties change due to twisting, crushing and/or twisting.

When installed, the light grid modules should be guided as well as possible in the profile housing in order to withstand mechanical shocks and vibrations, which can lead to damage or misalignment of the modules.

These requirements of easy insertion during assembly and a sufficiently tight fit when installed are contrary to each other.

So far, for example, spring elements have been arranged on the modules, which are supported on the inner wall of the profile. Care is taken to ensure that the friction between the module/springs and the profile is kept as low as possible and that the contact pressure of the springs is dimensioned to be strong enough so that the insertion force does not destroy the last module in the chain.

According to the prior art, it is also provided that the sensor housings are spread apart during production, while the chain of modules is arranged in the sensor housing. By removing the spread, the module chain is clamped in the sensor housing.

According to the prior art, complex design measures are therefore necessary in order to enable sensors to be installed.

An object of the invention is to provide an improved sensor housing with at least one optical element.

The object is achieved according to claim 1 by a sensor housing with at least one optical element, fixing means being arranged between the optical element and the sensor housing, the fixing means having swelling agent, with a swelling process of the swelling agent starting with a time delay and being effective and/or activatable, whereby the optical element is pressed against the sensor housing, whereby the optical element is fixed.

The solution according to the invention therefore consists in providing a fixing agent with a swelling agent, with the swelling agent swelling with a time delay after application or increasing its volume, for example only after an adjustment of the optical element and sensor housing.

Examples of swelling agents are, for example, the materials consisting of a polymer precursor and a hardener. For example, such swelling agents from the DE 42 32 059 A1 known.

Furthermore, the fixing agent can, for example, be an epoxy resin to which a swelling agent has been added. For example, such swelling agents from the DE 10 2006 004 577 A1 known.

The swelling agent does not swell immediately after leaving a pressure vessel, but only with a time delay. The time delay can be, for example, at least one minute, at least 5 minutes or, for example, at least 10 minutes.

According to the invention, the swelling process of the swelling agent can be activated.

For example, the swelling process is activated by heat. It can also be provided that the swelling process is started by mixing several components, for example a two-component mixture.

For example, it is the swelling agent to the substances which from the EP 0 909 783 B1 are known. Swelling agents that can be activated are also disclosed there.

The fixative can thus be applied in a compact form and can remain compact for a defined period of time even after a swelling process has started. During this time, the optical element can be adjusted to the sensor housing without there being any contact between the fixing agent and the sensor housing if the fixing agent was applied to the optical element. Of course, it can also be provided that the fixing agent is applied to the sensor housing and, after the swelling agent has swelled, reaches the optical element and thus the optical element and the sensor housing are pressed against one another.

For example, the fixing means has a surface with a low friction value, so that although there is a pressing effect between the optical element and the sensor housing, displacement is still possible, for example, in the event of expansion due to heat, but fixation occurs in the event of vibrations. For example, the friction value between the fixing means and the sensor housing or between the fixing means and the optical element can be reduced by means of a separating film.

The optical element can also be synonymous with an optical system. This makes it clear that the optical element or the optical system can have a plurality of components. For example, the optical system or the optical element has, for example, at least one printed circuit board, at least one tube and at least one lens, a lens system or an optical system. The optical element can also be arranged on a carrier. For example, the optical system should be aligned.

For example, optical elements can be pressed onto defined end stops in the sensor housing and fixed there independently without prior positioning. Here, for example, backlash-free bearings are possible, which can have a positive effect on vibration/shock loads.

According to the invention, for example, an insertion force of the optical element into the sensor housing is reduced. This results in fewer mechanical forces on the sensor housing and/or the optical element. As a result, the optical element and/or the sensor housing can be made simpler mechanically or structurally. Furthermore, the risk of damage to the parts used during assembly is reduced. Furthermore, no complex assembly tools are necessary, but the assembly can be carried out manually or even mechanically without great effort.

Thereby. that the optical element and/or the sensor housing is mechanically or structurally less complex, the optical element and/or the sensor housing can be made smaller and more compact, for example. As a result, the internal volume of the sensor housing can also be reduced, as a result of which the condensation behavior of the sensor is improved, for example, since there is less air volume inside the sensor.

In a development of the invention, the fixing means is an adhesive, in particular a liquid adhesive or a foam adhesive tape. As a result, in addition to the pressing effect, an integral connection is achieved. This achieves a more stable connection, which causes an effective and permanent connection between the optical element and the sensor housing even under high vibration/shock loads.

In a development of the invention, a period of time for the onset of the swelling process of the swelling agent can be set or specified.

In a development of the invention, a swelling process of the swelling agent is activated by energy radiation.

For example, the swelling process can be activated by means of energy irradiation, for example by means of light or UV light. Furthermore, the swelling process can also be activated by means of thermal radiation or generally by means of electromagnetic radiation.

For example, it is the swelling agent to substances according to EP 0 909 783 B1 Which can be activated by means of energy irradiation, for example by means of UV radiation.

In a development of the invention, the sensor housing is a sensor housing of an optoelectronic sensor. An optoelectronic sensor is, for example, a light barrier, a light scanner, a distance sensor or a similar sensor. Such optoelectronic sensors have at least one light transmitter and at least one light receiver. Furthermore, such an optoelectronic sensor has a control and evaluation unit which controls the light transmitter and evaluates the light receiver. Furthermore, such an optoelectronic sensor has at least one output or at least one output interface in order to provide the sensor result or the detection result. In the case of such optoelectronic sensors, it is important that the optical element is and remains precisely fixed in its intended position. For example to a reference surface, which is provided for example by the sensor housing. The more precisely the optical element is fixed, the higher the quality of the optoelectronic sensor. The optical element can be an optical module. The optical module can have at least one lens, optionally a tube, and optionally also a printed circuit board.

In a development of the invention, the sensor housing is a light grid housing. A light grid has a multiplicity of parallel optical axes, each of which is formed by a transmitter/receiver pair. This creates a protective field between the light grid housings. Such protective fields can, for example, have a height of up to approx. 2 m or 3 m. However, protective field heights of only 100 mm, for example, are also provided. In this case, protective field lengths are provided by different light grid housings, the light grid housings having length differences of, for example, 100 mm or 150 mm.

The optical element is formed in the light grid, for example, by an optical module chain with a large number of light transmitters and/or light receivers. For this purpose, the optical module chain in turn has, for example, a large number of individual modules which are connected to one another in succession and which form the optical module chain. The optical module chain has almost the same length as the light grid housing. The optical module chain is first connected to the fixative during production. Then the swelling agent of the fixative is activated. The optical module chain is then pushed into the light grid housing and adjusted. After the swelling agent has swelled, the optical module chain is finally fixed in the light grid housing. The swelling agent can also only be activated when the optical module chain has already been pushed into the light grid housing. This can be done, for example, by heat or, for example, by energy radiation through a front pane of the light grid housing.

In a development of the invention, the optical element is an optical lens. The lens can be, for example, a converging lens or, for example, a multiple lens or combination lens. For example, the lens can also be a free-form lens or the like.

In a development of the invention, the optical element has a series arrangement of optical lenses. For this purpose, for example, a plurality of lenses are arranged one after the other in a row as a one-piece element. For this purpose, the optical axes of the individual lenses are aligned parallel to one another, for example. Such row arrangements are particularly suitable, for example, for the production of light grids.

In a further development of the invention, the fixing agent is thermally conductive. As a result, improved heat conduction is produced between the optical element and the sensor housing, as a result of which thermomechanical stresses are reduced. Furthermore, for example, a high temperature or an excess temperature inside the sensor can be avoided, since there is improved thermal conductivity to the sensor housing.

In a further development of the invention, the fixing means is electrically conductive. This creates improved electrical conductivity between the optical element, in particular a printed circuit board of the optical element, and the sensor housing, as a result of which the electromagnetic behavior, or EMC behavior for short, of the sensor is improved. In particular, this can also prevent static charging of the optical elements.

• 1 und 2 jeweils ein Sensorgehäuse und ein optisches Element mit einem Fixiermittel.
• 3 bis 6 jeweils einen optoelektronischen Sensor mit einem Sensorgehäuse und einem optischen Element.
• 7 und 8 jeweils ein Schaumstoffklebeband.
• 9 bis 11 jeweils ein Lichtgittergehäuse für ein Lichtgitter.

The invention is explained below also with regard to further advantages and features with reference to the attached drawing based on exemplary embodiments. The figures of the drawing show in:

• 1 and 2 each a sensor housing and an optical element with a fixing agent.
• 3 until 6 each an optoelectronic sensor with a sensor housing and an optical element.
• 7 and 8th one piece of foam tape each.
• 9 until 11 one light grid housing each for one light grid.

In the following figures, identical parts are provided with identical reference numbers.

1 shows a sensor housing 1 with at least one optical element 2, with fixing means 3 being arranged between the optical element 2 and the sensor housing 1, with the fixing means 3 having swelling means 4, with a swelling process of the swelling means 4 starting with a time delay and being effective and/or activatable , whereby the optical element 2 is pressed against the sensor housing 1, whereby the optical element 2 is fixed to the sensor housing 1. According to 1 the swelling process has not yet started. According to 2 the swelling agent is swollen.

The swelling agent 4 thus swells with a time delay after application or increases its volume. The swelling agent does not swell immediately after leaving a pressure vessel, but only with a time delay after the optical element 2 and sensor housing 1 have been adjusted.

The fixing agent 3 can thus be applied in a compact manner and can remain compact for a defined period of time even after a swelling process has started. During this time, the optical element 2 can be adjusted to the sensor housing 1 without contact occurring between the fixing means 3 and the sensor housing 1 if the fixing means 3 was applied to the optical element 2 . It can of course also be provided that the fixing agent 3 is applied to the sensor housing 2 and after a swelling process of the swelling agent 4 reaches the optical element 2 and thus the optical element 2 and the sensor housing 1 are pressed against one another.

For example, the fixing means 3 has a surface with a low friction value, so that although there is a pressing effect between the optical element 2 and the sensor housing 1, a displacement is possible, for example, in the event of expansion due to heat, but fixation occurs in the event of vibrations. For example, the friction value between the fixing means 3 and the sensor housing 1 or between the fixing means 3 and the optical element 2 can be reduced by means of a separating film.

For example, optical elements 2 can be pressed onto defined end stops in the sensor housing 1 and fixed there independently without prior positioning. Here, for example, backlash-free bearings are possible, which can have a positive effect on vibration/shock loads.

For example, the fixing means 3 is an adhesive, in particular a liquid adhesive or a foam adhesive tape 13 according to FIG 7 and 8th . According to 7 the foam tape has its original volume. According to 8th part of the unrolled foam tape shows an increased volume caused by the swelling agents after a certain period of time.

For example, a period of time for the onset of the swelling process of the swelling agent 4 can be set or specified.

For example, the swelling process of the swelling agent 4 can be activated. For example, the swelling process is activated by heat. It can also be provided that the swelling process is started by mixing several components, for example a two-component mixture.

For example, the swelling process can be activated by means of energy irradiation, for example by means of UV light.

For example, the sensor housing 1 is a sensor housing 1 of an optoelectronic sensor 5, as in 5 shown.

The optical element 2 can be an optical module, as in 3 until 5 shown. The optical module can have at least one lens 7, optionally a tube, and optionally also a printed circuit board 9.

According to 3 the optical element 2 and the sensor housing are prepared for assembly. According to 4 the fixing agent 3 with the swelling agent 4 was applied to the optical element. For example, manually or also automatically with an automation device. According to 5 the optical element 2 is pushed into the sensor housing. For example, manually or also automatically with an automation device. The swelling agent is still compact in its original state. After the optical element 2 according to 6 was finally positioned or adjusted in the sensor housing, the swelling agent of the fixing agent is swollen and fixes the optical element in the sensor housing.

For example, the sensor housing 1 is a light grid housing 6 according to FIG 9 until 11 . A light grid has a multiplicity of parallel optical axes, each of which is formed by a transmitter/receiver pair. This creates a protective field between the light grid housings.

The optical element 2 is formed in the light grid, for example, by an optical module chain with a large number of light transmitters and/or light receivers. For this purpose, the optical module chain in turn has, for example, a large number of individual modules which are connected to one another in succession and which form an optical module chain. The optical module chain has almost the same length as the light grid housing 6. During production, the optical module chain is first connected to the fixing means 3, for example by means of an application device 12 according to FIG 9 .

The swelling agent 4 of the fixing agent 3 is then activated. For example, by means of a lamp 10 according to 9 . Then the optical module chain is inserted into the light curtain housing 6 and adjusted according to the 10 and 11 . For example, by means of an assembly ramp 11. After the swelling agent 4 has swelled, the optical module chain is finally fixed in the light grid housing 6 according to FIG 11 . The swelling agent 4 can also only be activated when the optical module chain has already been pushed into the light grid housing 6 . This can be done, for example, by heat or, for example, by energy radiation through a front pane 8 of the light grid housing 6 .

For example, the optical element 2 is an optical lens 7 according to FIG 1 . The lens 7 can be, for example, a converging lens or, for example, a multiple lens or combination lens. For example, the lens 7 can also be a free-form lens or the like.

For example, the optical element 2 has a row arrangement of optical lenses 7 according to FIG 9 , 10 and 11 . For this purpose, for example, a plurality of lenses 7 are arranged one after the other in a row as a one-piece element. For this purpose, the optical axes of the individual lenses are aligned parallel to one another, for example. Such row arrangements are particularly suitable, for example, for the production of light grids.

For example, the fixative is thermally conductive. As a result, improved heat conduction is produced between the optical element and the sensor housing, as a result of which thermomechanical stresses are reduced.

For example, the fixative is electrically conductive. As a result, improved electrical conductivity is created between the optical element, in particular a printed circuit board of the optical element, and the sensor housing, as a result of which the electromagnetic behavior, or EMC behavior for short, of the sensor is improved.

reference list

1

sensor housing

2

optical element

3

fixer

4

swelling agent

5

optoelectronic sensor

6

light grid housing

7

lens

8th

windscreen

9

circuit board

10

lamp

11

assembly ramp

12

application device

13

foam tape

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 4232059 A1 [0013]
• DE 102006004577 A1 [0014]
• EP 0909783 B1 [0018, 0029]

Claims (10)

Sensor housing (1) with at least one optical element (2), characterized in that fixing means (3) are arranged between the optical element (2) and the sensor housing (1), the fixing means (3) having swelling means (4), wherein a swelling process of the swelling agent (4) starts with a time delay and is effective and/or can be activated, whereby the optical element (2) is pressed against the sensor housing (1), whereby the optical element (2) is fixed. Sensor housing (1) after claim 1 , characterized in that the fixing means (3) is an adhesive, in particular a liquid adhesive or a foam adhesive tape. Sensor housing (1) according to at least one of the preceding claims, characterized in that the duration of the swelling process of the swelling agent (4) can be set or specified. Sensor housing (1) according to at least one of the preceding claims, characterized in that a swelling process of the swelling agent (4) is activated by energy radiation. Sensor housing (1) according to at least one of the preceding claims, characterized in that the sensor housing (1) is a sensor housing (1) of an optoelectronic sensor (5). Sensor housing (1) according to at least one of the preceding claims, characterized in that the sensor housing (1) is a light grid housing (6). Sensor housing (1) according to at least one of the preceding claims, characterized in that the optical element is an optical lens. Sensor housing (1) according to at least one of the preceding claims, characterized in that the optical element has a row arrangement of optical lenses. Sensor housing (1) according to at least one of the preceding claims, characterized in that the fixing means is thermally conductive. Sensor housing (1) according to at least one of the preceding claims, characterized in that the fixing means is electrically conductive.

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