WO2011039377A1

WO2011039377A1 - Device for passively tracking the movement of the sun

Info

Publication number: WO2011039377A1
Application number: PCT/EP2010/064747
Authority: WO
Inventors: Thomas Manfredotti
Original assignee: Dynalya
Priority date: 2009-10-02
Filing date: 2010-10-04
Publication date: 2011-04-07
Also published as: FR2950988B1; FR2950988A1

Abstract

The present invention relates to a device for passively tracking the movement of the sun, comprising a first expansion member (2) and a second expansion member (3), which are reversibly expandable in accordance with the temperature, and a means for detecting an expansion amplitude differential between the first expansion member (2) and the second expansion member (3) which are capable of moving a member to be moved in accordance with said differential, characterized in that the device includes means for detecting the expansion amplitude of the least expanded expansion member and a first control means capable of moving the member to be moved, said detection means being configured to generate a movement of the first control means in accordance with said amplitude. The present invention can be used in all fields where it is important to track the movement of the sun in terms of the azimuth and/or elevation thereof while taking the environment, such as the ambient temperature, into account.

Description

"Device for passive tracking of the movement of the sun"

The present invention relates to a device for passive tracking of the movement of the sun and its applications.

The invention will find its application in any system where it is important to follow the movement of the sun such as for example the field of solar energy where the orientation of the solar energy collection device is essential for optimum performance or good for roof windows especially where it is useful to reflect the light rays in a controlled manner towards the interior of the building.

Already known devices for tracking the movement of the sun are "active", that is to say they require a motor to generate the displacement of the sun.

This type of device therefore has the disadvantage of requiring a power source, often electric. The mounting of the device is complex and the use is energy consuming.

Other devices called "passive" do not require external energy, that is to say that it is only solar energy that is used to generate a displacement function of the movement of the sun.

These devices operate, for the most part, by detecting a difference between two means receiving solar radiation. According to the movement of the sun, one of the two means receives more rays than the other means. There is a difference between the two means. When the device detects a difference, it is translated by a movement intended to follow the movement of the sun.

No. 4,283,588 discloses a passive sun tracking device in which the photovoltaic panel is pivotally displaced to follow the sun. The photovoltaic panel is animated only by a single movement depending on the movement of the sun.

One of the disadvantages of these types of devices, whether active or passive, is that they often have only one type of motion to track the movement of the sun. In addition, only a difference between these two means is detected.

There is therefore the need to provide a device for tracking the movement of the sun that overcomes all or part of these disadvantages to present a better efficiency.

To this end, the present invention relates to a device for passive tracking of the movement of the sun which comprises a first and a second expansion member whose expansion amplitude differential is detected by detection means connected to control means configured to to go from an inactive state to an active state when the differential of the amplitude of expansion is zero.

Preferably, the present invention relates to a device for passive monitoring of the movement of the sun which comprises a first and a second expansion member whose expansion amplitude of the least dilated expansion member is detected by detection means connected to control means configured to operate a movement of a member to move according to said amplitude.

The first dilation member and the second dilation member are configured to expand in a reversible manner by increasing or decreasing their temperature.

The device according to the invention makes it possible to detect a differential of amplitude of expansion possibly zero and to generate an action thanks to the control means which then pass from an inactivated state to an activated state or vice versa.

When the expansion amplitude differential is zero, this means that, for example, the first expansion member and the second expansion member are dilated identically or stably with respect to each other and therefore their temperature is possibly identical. In particular, when the differential amplitude of expansion is zero, there is activation of the control means. That is to say, the temperatures of the first expansion member and the second expansion member are identical and advantageously that the amplitude of expansion of the first member of the Expansion and / or the second expansion member has reached a certain predefined threshold corresponding to a predetermined ambient temperature.

Thus, according to a preferred embodiment, the control means pass from an inactive state to an active state when the expansion amplitude differential is zero and the amplitude of expansion has reached a predefined threshold.

This embodiment makes it possible to take into account the entire environment and in particular the ambient temperature.

Preferably, the device according to the invention also comprises second control means also connected to the detection means but which are configured to go from an inactive state to an active state when the differential of the amplitude of expansion is not zero.

Thus, the invention detects simultaneously and independently the movement of the sun and the ambient temperature.

The invention makes it possible to monitor the displacement of the sun in azimuth or elevation, preferably in azimuth and advantageously in azimuth and elevation. It is particularly effective that the device follows the movement of the sun in these two directions so that the orientation of the device relative to the sun is improved.

Other objects and advantages will become apparent from the following description of a preferred embodiment of the invention which is not however limiting.

It should first be recalled that the present invention relates to a device for passive tracking of the movement of the sun comprising a first expansion member and a second expansion member configured to expand in a reversible manner to a rise in temperature and means of detecting the difference in amplitude of expansion between the first expansion member and the second expansion member, characterized in that it comprises first control means connected to the detection means and control means so that the first means of control switch from an inactive state to an active state when the detection means detects a zero expansion amplitude differential and the expansion amplitude has reached a predefined threshold.

More specifically, the invention relates to a device for the movement of the sun comprising a first expansion member and a second expansion member which can be expanded in a reversible manner as a function of the temperature, and means for detecting a differential of amplitude of expansion between the first dilation member and the second dilation member able to make a movement on a member to move according to said differential characterized in that it comprises means for detecting the amplitude of expansion of the dilation organ the least expanded and first control means adapted to effect a movement of the member to move, said detection means being configured to generate a displacement of the first control means function of said amplitude.

According to preferred but non-limiting variants of the invention, the device according to the invention is such that:

it comprises means for controlling the first control means so that the first control means move from an inactive state to an active state when the detection means detect an amplitude of expansion of the dilated expansion member and that the control means detect that the amplitude of expansion of the least dilated expansion member has exceeded a predefined threshold,

the means for detecting the amplitude of expansion of the least dilated expansion member comprise a rigid frame configured to cooperate with the first control means and rigidly fixed to one of the ends of the first dilation member and the second member so that the frame has only one degree of freedom relative to the first and second expansion members, the first control means switches from an active state to an inactive state when the detection means detects an amplitude of dilation of the least dilated dilation member and that the control means detect that the expansion amplitude of the least dilated expansion member has passed below a predefined threshold,

it comprises second control means connected to the means for detecting a differential amplitude of expansion between the first expansion member and the second expansion member and configured to go from an inactive state to an active state when the means for detection detects a differential nonzero expansion amplitude the second control means are configured to operate at least one rotational movement along an axis of rotation to the member to move which are integral with the first expansion member and the second member of dilation

it comprises at least one screen arranged to separate the first dilation member from the second dilation member and project a shadow depending on the displacement of the sun on one of the two expansion members and / or depending on the position of the two expansion members, the first dilation member and the second dilation member are configured to expand in a longitudinal direction so as to generate a translational movement,

means for transforming a translation movement of the first expansion member and / or the second expansion member into a rotational movement,

the second control means are intended for monitoring the movement of the sun in azimuth and / or in elevation,

it comprises means for transforming a translational movement of the first expansion member and / or the second expansion member into a rotational movement along an axis of rotation when the means for detecting a difference in amplitude of expansion between the first dilation member and the second dilation member detect a non-zero expansion amplitude differential,

the second control means comprise a coupling member configured to associate with the first rotational movement a second rotational movement as a function of the first rotational movement along an axis of rotation,

the first rotational movement and the second rotational movement are substantially perpendicular axes,

it comprises means for amplifying the displacement in translation of the first dilation member and the second dilation member, it comprises a screen is arranged to separate the first dilation member from the second dilation member, preferably to project a shadow on at least one of the two expansion members, the detection means comprise a rigid frame configured to cooperate with the first control means and rigidly fixed to one of the ends of the first expansion member and the second expansion member so that the frame has only one degree of freedom, it comprises second control means connected to the detection means and configured to go from an inactive state to an active state when the detection means detect a differential amplitude of expansion not no,

the second control means are configured to generate at least one rotational movement, The invention also relates to a light ray reflection system comprising a tracking device as described above and a plurality of articulated movable blades configured to cooperate and be controlled by the device.

Another object of the invention is a system of solar collector panels comprising a tracking device and at least one solar collector means configured to cooperate and be controlled by the device.

The accompanying drawings are given by way of example and are not limiting of the invention. They represent only one embodiment of the invention and will make it easy to understand.

Figure 1: view of the device according to the invention in lower side view.

Figure 2: view of the device according to the invention in an upper side view.

Figure 3: Detail view of the coupling member according to the invention.

Figure 4: view of the device according to the invention integrated in a housing in view from below.

Figure 5: view of the device according to the invention according to Figure 4 in front side view.

Figures 6 and 7: views of the device according to the invention mounted in a light ray reflection system in lateral view in two different positions of the reflection plates.

8: detail view of the inclination means of the reflection plates according to FIGS. 6 and 7.

Figures 9 and 10: views of the reflection system according to the invention without the tracking device in front view in two different positions of the reflection plates.

Figure 1 1: view of a reflection system according to the invention adapted in a dome of a roof window.

Figure 12: schematic diagram of the device according to the invention

The present invention relates to a device for passive tracking of the movement of the sun.

Passive tracking is understood to mean that the orientation of the device according to the invention is modified as a function of the displacement of the sun without requiring any energy other than the thermal or photovoltaic energy of the solar radiation.

The device 1 according to the invention comprises a first expansion member 2 and a second expansion member 3 configured to expand in a reversible manner during variations in their temperatures.

The first expansion member 2 and the second expansion member 3 are preferably mounted integral with a movable frame 32. The movable frame 32 is connected to a member to move to follow the movement of the sun. The dilatation is an increase of the volume of a body under the influence of a variation of temperature without change of its nature or its constitution.

By way of example, the variations in expansion of the two expansion members 2-3 result in a change in the length of the expansion members 2-3.

The first expansion member 2 and the second expansion member 3 constitute the driving elements of the device 1 according to the invention by converting the thermal radiation of the sun into movements and efforts.

Expansion can be achieved by dilating solids, liquids or gases. For example, bimetallic, shape-memory or phase-change materials may be used, but also elastomers or polymers.

The first expansion member 2 and the second expansion member 3 are advantageously arranged parallel to each other.

When the sun moves in the sky during a day, the first expansion member 2 and the second expansion member 3 receive solar radiation in a different manner.

For example if the device is in a first position where the two expansion members 2, 3 receive almost the same solar radiation, if the sun then moves alone one of the two expansion members 2, 3 will receive fully the solar radiation.

The first expansion member 2 and the second expansion member 3 are connected to means for detecting the differential of the amplitude of expansion between them.

The detection means are configured to firstly detect the amplitude of expansion of one of the two expansion members 2-3 whose expansion is the lowest and secondly to detect the differential of the amplitude of expansion of the two expansion members 2-3.

The detection means are advantageously configured to cooperate with firstly the first control means and secondly second control means.

More precisely, the detection means are configured to respectively print a movement to the first control means as a function of the value of the expansion amplitude of the least dilated expansion member and a movement to the second control means depending on the value. of the differential of the expansion amplitude of the two expansion members 2-3.

The first control means are able to make a first movement on a member to move. While the second control means are able to make a second movement on the member to move. The expansion members 2 - 3 are intended to receive the sun's rays. Preferably, only one of the two expansion members 2-3 receives the sun's rays at a time. Thus, the least dilated dilation member corresponds to the dilation member not receiving the sun's rays, the expansion member is separated from the sun's rays for example by a screen. The dilatation that this organ undergoes is due only to the variation of the ambient temperature.

The organ to move so that it follows the movement of the sun can be of different type: mirror blades for roof window or photovoltaic panel.

According to one possibility, the device comprises means for controlling the first control means. These control means are configured to vary the function linking the displacement of the detection means and the displacement of the first control means.

The control means may make it possible to define a threshold for activating and deactivating the first control means. Alternatively or additionally, the control means can be used to define the law of the function between the displacement of the detection means and the displacement of the first control means.

According to the invention, when one of the two expansion members 2-3 receives more sunlight, it undergoes a greater expansion than the other dilation member. A differential amplitude of expansion is then detected by the detection means and the second control means operate a movement on the member to be moved.

In parallel, mainly when the ambient temperature varies, the two expansion members, whatever their position vis-a-vis the sun and their respective amplitude of expansion, will undergo a common expansion due to the ambient temperature. The amplitude of expansion of the dilated dilation member corresponds to the common range of the amplitude of expansion of the two expansion members. The amplitude of expansion of the dilated dilation member will correspond to the variation, increase or decrease of the ambient temperature. This amplitude of expansion is detected by the detection means which act by moving the first control means as a function of the value of said amplitude. The first control means operates a movement on the member to be moved.

In the remainder of the description, the expression "differential of the amplitude of non-zero expansion" may occur when "the value of the amplitude of expansion of the dilated dilation member is non-zero" According to the invention, compared to a reference expansion state, advantageously minimal, first and second expansion members takes advantage of two elongation values due to the expansion:

a value corresponding to an amplitude of expansion common to both expansion members, that is to say the length of the elongation of the least dilated organ. This value is exploited in relation to the first control means.

A value corresponding to the difference in elongation length of the two expansion members. This value, differential, is exploited in relation to the second control means.

Thus, two distinct values, from only two expansion members, allow two movement commands.

The device 1 according to the invention further comprises first control means connected to the detection means. The first control means are configured to go from an inactive state to an active state when the detection means detect a differential of the zero expansion amplitude.

For example, when the first dilation member 2 and the second dilation member 3 have an equivalent expansion amplitude, then the differential of the expansion amplitude is zero. This zero differential causes activation of the control means and their transition from an inactive state to an active state.

Advantageously, activation means first control means, an actuation of an external device generating an action such as a movement.

The tracking device advantageously comprises means for controlling the transition from the inactive state to the active state of the control means. The control means are intended in particular to define a threshold of the amplitude of expansion of the expansion members 2, 3 so that the control means pass from an inactivated state to an activated state when the threshold is reached and preferably exceeded.

Advantageously, the first control means pass from an activated state to an inactivated state when the threshold is reached and preferably when the amplitude of expansion goes below the predefined threshold.

According to one possibility, these control means make it possible to avoid that each time the device is in equilibrium, that is to say that the variation of the amplitude of expansion of the two expansion members is identical, the control means are activated or inactivated.

According to a preferred embodiment, the device 1 comprises second control means connected to the detection means. The second means of control are also configured to go from an idle state to an active state but when the detecting means detects a nonzero expansion amplitude differential.

Advantageously, the device 1 according to the invention thus makes it possible to detect a zero expansion differential as well as a non-zero expansion differential. In each of these two cases, an action is generated that is to say respectively transition from an inactive state to an active state of the first control means or the second control means.

Advantageously, each of the first control means and the second control means control separate actions.

Preferably, the control means control an action related to monitoring the movement of the sun in azimuth and / or elevation.

The azimuth is a horizontal angle between the direction of an object, here the sun, and a direction of reference, here the geographical north. The azimuth corresponds to the movement of the sun from east to west.

Elevation is the vertical angle that corresponds to the movement of the sun relative to the horizon.

The first expansion member 2 and the second expansion member 3 each advantageously comprise two ends to which the detection means are connected.

As shown in Figures 1 and 2, the expansion members 2, 3 are members configured to expand in a longitudinal direction. As a preferred example, the first expansion member 2 and the second expansion member 3 are elongated.

Advantageously, the first expansion member 2 and the second expansion member 3 are connected by one end, on the same side, to a rigid frame 7 partially forming the detection means.

This frame 7, possibly of rectangular shape, is movable only with one degree of freedom relative to the two expansion members 2-3. The rigid frame 7 is mobile in particular when the amplitude of expansion between the first expansion member 2 and the second expansion member 3 is equivalent, that is to say that the expansion amplitude differential is zero. The expansion amplitude of the dilated dilation member is non-zero. In this situation, the frame 7 is displaced, in the figures pivoting, controlling for example by activating the first control means by passing from an inactive state to an active state or vice versa. In the embodiment where the device comprises control means, the frame 7 will be moved but depending on whether the threshold has been reached or not, the first control means will be activated or not. In the embodiment where the control means do not define a threshold, the first control means will undergo a displacement function of the control means.

For example, the control means comprise a rod 1 1 fixed rigidly to the frame 7 and provided with a plurality of notches 12 arranged regularly.

These notches 12 are intended to receive the end of a movable element, for example elongated such as a rod 25, allowing its other end to generate an action. Depending on the positioning of this element on the rod 1 1, then it will not be moved in the same way during a movement of the frame 7. For example, if the element is located on the rod 1 1 at most close to its attachment to the frame 7 so that the element undergoes minimal movement, it is necessary that the frame 7 undergoes significant displacement. Conversely, when an element is located on the rod 1 1 at the end farthest from the frame 7 then even a minimal displacement of the frame 7 will cause a consequent displacement of the element.

The other end of the first expansion member 2 and the second expansion member 3 are also connected to the detection means and the second control means.

By way of example and as shown in the figures, the detection means located at this end of the first expansion member 2 and the second expansion member 3 allowing the first expansion member 2 or the second expansion member 3 can expand and act on the detection means independently of one another.

For this purpose, the first expansion member 2 and the second expansion member

3 are respectively connected for example to a rod 14 itself connected to a lever 15. The links 14 and the levers 15 advantageously constitute a system for amplifying the movement of the expansion of the first expansion member 2 and the second expansion member 3. Thus, a small amplitude of expansion of one of the two expansion members 2, 3 will be detected and transmitted.

As an example shown, the amplification system comprises a first lever arm, the rod 14, at each end of an expansion member 2 -3 exerting a first amplification. This first lever arm is connected to a second lever arm, the lever 15.

These detection and amplification means constituted in part by the rods

14 and the levers 15 are preferentially connected to means for transforming the movement 8 advantageously intended to transform the movement generated by the first expansion member 2 and the second expansion member 3 in another movement.

By way of preference, the movement generated by the first expansion member 2 and second expansion member 2, 3, and in particular through the detection means the links 14 and the levers 15, is a translational movement. This translational movement is then transformed by the motion transformation means 8 into a rotational movement.

According to a non-limiting embodiment, the motion transformation means 8 comprises a cable system 16 running through sheaves 17 and pulleys 19.

The motion transformation means 8 may also be made by a set of gears or cables or chains or rods or by a hydraulic system or by a modification of the position of the center of gravity of the device.

The tracking device is advantageously rotatable about an axis of rotation 18. This axis of rotation 18 is preferably parallel to the two expansion members 2, 3.

Preferably, the rotational movement is applied to the axis of rotation 18.

According to the invention, the second control means are intended to monitor the movement of the sun in azimuth, that is to say that when the expansion differential is not zero then the second control means go from an inactivated state to an activated state: a rotational movement is applied to the axis of rotation 18 allowing the device 1 to follow the movement of the sun in azimuth. Advantageously, the rotation of the axis of rotation 18 causes the displacement of the member to be moved but also of the tracking device 1. The two expansion members 2-3 are simultaneously movable to the member to be moved.

Advantageously, the device 1 according to the invention also follows the displacement of the sun in elevation.

According to a first possibility, a second device comprising a first expansion member and a second expansion member associated with detection means and control means is placed in series of the first device with an offset axis of rotation and advantageously substantially perpendicular to the rotation axis 18. According to a second simpler possibility, the device 1 according to the invention comprises a coupling member configured to associate with the first rotational movement of the axis of rotation 18 a second rotational movement. The second rotational movement is a function of the first rotational movement. By way of example only, the coupling member comprises a cam 9 placed on the axis of rotation 18 and cooperating with a roller 20 so that when the axis of rotation 18 undergoes a rotational movement then it is transferred to the roller 20 with a shift function of the cam 9.

As with the first possibility, it is advantageous that the first rotational movement and the right angle of rotation are sufficiently perpendicular.

According to another possibility, the displacement induced by the first control means on the organ to be displaced corresponds to a follow-up of the sun in elevation.

It should be noted that it is possible that the second control means are intended to follow the tracking of the displacement of the sun in elevation while the coupling member allows azimuth tracking.

Thus the device 1 according to the invention is particularly complete since it allows the passive tracking of the displacement of the sun in azimuth and elevation and it also makes it possible to generate an action especially when the device is at equilibrium that is that is, the first expansion member 2 and the second expansion member 3 are expanded in an identical or constant manner, advantageously as a function of the ambient temperature.

For the device 1 to work properly, the first expansion member 2 and the second expansion member 3 advantageously receive the sun rays in a different manner, permanently during the operation of said device, so as to undergo a different expansion one of the other and thus generate a differential detected by the detection means then causing an activation of the second control means for generating a movement of the organ to be moved for tracking the movement of the sun. So as to improve the device 1, it comprises at least one screen 10 configured to promote the illumination of one of the two expansion members 2, 3. The screen 10 thus promotes the difference in amplitude of expansion between the two expansion members 2, 3. Advantageously, the screen 10 is arranged to separate the two expansion members 2, 3 from one another. For example, the screen 10 is disposed between the two expansion members 2, 3.

Preferably, the screen 10 has an envelope shape, FIGS. 4 to 7 and

1 1 -12, around each of the expansion members 2 - 3 so that at least one of these two bodies of dilatation 2- 3 is in the shade, does not receive rays of the sun.

This allows the angular displacement of the device 1 to be proportional to the illumination by the sun's rays of the first expansion member 2 or the second dilation member 3.

The rotation of the device 1 will project the shadow of a screen 10, in this case the front part, on the dilation member 2 - 3 exposed to the sun and allow to arrive at a position of equilibrium when this shadow will have covered a determined part of the dilation member 2 - 3. When the sun moves, the shadow will shift and cover a little less the dilator 2 - 3. The temperature will increase which will cause its dilate and generate the rotation of the set until a new equilibrium is found.

The screen 10 is advantageously reflective and is associated with a concentrator in order to converge the solar radiation on the first expansion member 2 or the second expansion member 3 in particular for the low rays on the horizon.

In order to be protected, the device 1 according to the invention can be placed in a housing 21 forming a mobile frame 32.

According to the invention, the device 1 advantageously comprises a tensioning means 13. This tensioning means is intended to compress or pull the first expansion member 2 and the second expansion member 3 to cancel the operating games by application of an effort or a couple. It also allows a return to neutral position when the sun is down. This tensioning means 13 comprises, for example, springs or operates by gravity.

Optionally, non-return means are inserted into the device 1 so as to prevent a traction of the first expansion member 2 and the second expansion member 3 involuntarily. In case of involuntary traction, the non-return means rigidly links the first expansion member 2 and the second expansion member 3 to the rest of the device 1 and in particular to the mobile frame 32.

These means are particularly useful when the expansion members 2, 3 are hydraulic tanks. For example, it will be oil, but any element that expands linearly or non-linearly may be suitable. In this tank plunges a cylinder rod that transforms the expansion of the fluid.

The non-return means serve to prevent a negative pressure being applied. Indeed, the rigidity of the cylinder is very important when the cylinder rod sinks into the tank but almost zero in the other direction, a vacuum bubble that can be created. The non-return means make it possible to lock the mechanism in case of wind gusts which dispenses with the use of hydraulic dampers.

According to one embodiment, it is therefore a set of balls held in a cage connected to the cylinder rod and can be expanded by a conical or spherical piece connected to the rest of the mechanism. If the fluid expands in the cylinder rod, it pushes the spherical part and the balls do not touch the outer casing.

If we pull the spherical part, the rod of the cylinder will oppose a resistance which will have the effect of removing the balls that will come to press the housing.

If the pressure angle between the spherical part is smaller than the friction cone between the balls and the housing, the device is self-locking and prevents pulling on the cylinder rod. The spherical portion also allows a slight rolling of the assembly.

The first control means are activated when a differential of zero expansion amplitude is detected by the detection means advantageously for controlling and generating an action depending on the environment other than direct solar radiation. Indeed, when the expansion amplitude differential of the first expansion member 2 and the second expansion member 3 is zero, this means that one of the expansion members 2 or 3 receives a solar radiation which increases its temperature and generates a dilation of this dilation member 2. While the other expansion member 2 or 3 does not receive the same solar radiation but the ambient temperature generates a dilation of the second expansion member 3 equivalent to a portion of that of the first expansion member 2. Thus, these first control means can generate an action depending on the ambient temperature and in particular when the ambient temperature reaches a certain threshold.

According to a first variant, the moving member of the device 1 according to the invention is a light ray reflection system. For example, this reflection system is disposed at a window, especially at a roof window, so as to increase the lighting inside a building by correctly directing the light rays throughout the building.

According to this variant, the light ray reflection system comprises a plurality of blades 22 configured to reflect the light rays. Thus, the device 1 according to the invention associated with this light reflection system will track the movement of the sun by orienting the blades 22 adequately so as to orient the sun's rays inside the building and increase the lighting . According to the invention, the device 1 can also, when the ambient temperature increases and reaches a predetermined threshold, deflect the light rays outwardly thus preventing their penetration and thus limiting the rise in temperature inside the building. According to one possibility, the deviation of the light rays can be progressive.

As shown in the figures, the light ray reflection system comprises a plurality of blades 22 mounted on supports 27. Advantageously, the blades 22 are articulated between two "U" supports mounted opposite one another. the other. The two supports 27 are articulated with respect to each other by articulations 30.

This reflection system and in particular the supports 27 are controlled by a return 29 controlled by the first control means and the second control means.

The supports 27 are mounted either perpendicular to the axis of rotation 18 of the device 1 or else form an angle different from 90 ° with this axis of rotation 18 so as to recover more light rays, especially at sunrise and sunset when the light rays are low.

According to this variant, when the sun rises, it begins to illuminate at least in part the first expansion member 2, the latter increases in temperature and expands generating a non-zero expansion amplitude differential detected by the detection means . There is activation of the second control means. When the second control means move from an inactive state to an active state, there is generated a rotational movement of the axis of rotation 18 of a rotation angle substantially equal to the azimuth of the sun at this point. precise moment. Alternatively, the rotation of the reflection system and the tracking device 1 allows the second expansion member 3 also receives light rays identically to the first expansion member 2 and thus again obtain a zero expansion differential. The balance is reached. When the sun continues moving during the day, only the first dilation 2 will be lit again and so on.

Whether with the use of screen or not, the tracking device 1 will not be perfectly aligned with the sun because the expansion members 2, 3 must receive a difference in light radiation capable of generating the amplitude differential of dilation allowing the rotation of the tracking device 1 by an angle substantially equal to the azimuth The difference between the position of the sun and the tracking device 1 will depend on the shadow projected on the expansion members 2 and 3.

So that the blades 22 are aligned more precisely towards the sun, it will be advantageous to use a means for slightly increasing the angular displacement of the blades 22 with for example a gear ratio greater than 1 or a suitable combination of links between the tracking device 1 and the blades 22.

The device 1 according to the invention allows the reflection system to be rotated according to the azimuth of the sun but also a tilting movement of the blades 22 according to the azimuth of the sun, by means of the coupling member here the cam 9.

The first control means are configured so that they change from an inactive state to an active state when the expansion differential is zero and the expansion of the first expansion member 2 and the second expansion member 3 reaches a predefined threshold. For this, the device comprises control means. The first control means and in particular the frame 7 are connected to a rod 1 1 which is movable in a single degree of rotation according to the movement of the frame 7. This rod 1 1 is provided with notches 12 on which is mounted a rod 24 connecting the first control means to the return means 29. According to the positioning of the rod 24 on the rod 1 1, a small displacement of the latter will cause a displacement of the rod 24 and therefore the return 29 or otherwise it will require a significant movement of the rod 1 1. It is thus possible through the notches 12 of the rod 1 1 to adjust the threshold that must reach the expansion of the first expansion member 2 and the second expansion member 3 to generate an action.

In this variant, the action generated by the first control means is advantageously a tilting of the blades 22 so as to reflect the light rays to the outside.

The reflection system according to the invention is advantageously placed in a roof window under a transparent dome 26. The blades 22 may be of mirror material or of selective transparent material which reflect light for certain ranges of inclination of the light rays touching the blade 22.

According to a second variant of the invention, the device moving member 1 is a solar energy collection system.

The solar energy capture system may be a photovoltaic panel or a means for capturing the thermal energy of the solar radiation. For solar energy collector panels, it is important to increase their efficiency that their orientation towards the sun is the most favorable. The device 1 according the invention will allow azimuth orientation and elevation solar energy collection panels as a function of the movement of the sun. In this case, the first control means have for example the function of modifying the inclination of the axis of rotation 18 of the tracking of the displacement of the sun in azimuth as a function of the ambient temperature, for example to give more inclination to photovoltaic panels in summer when it's hot to capture the sun's rays that are higher in the sky.

REFERENCES

1. Tracking device

2. First dilatation organ

3. Second dilation organ

7. Framework

8. Processing medium

9. Cam

10. Screen

1 1. Rod

12. Notch

13. Means of tensioning

14. Links

15. Levers

16. Cable

17. Réa

18. Rotation axis

19. Pulley

20. Roller

21. box

22. Blades

23. Means for inclining the blades

24. Means for tilting blades

25. Stem

26. Dome

27. Support

28. Notch

29. Referral

30. Articulation

31. Check

32. Mobile chassis

33. Sun

Claims

1. Device (1) for passive monitoring of the movement of the sun, comprising a first expansion member (2) and a second expansion member (3) that can be expanded in a reversible manner as a function of the temperature and means for detecting an amplitude differential of dilation between the first dilation member (2) and the second dilation member (3) able to make a movement on a member to move according to said differential

characterized by the fact that it comprises

means for detecting the amplitude of expansion of the least dilated expansion member and first control means adapted to make a movement of the member to be moved, said detection means being configured to generate a displacement of the first means control function of said amplitude.

Device according to claim 1 comprising means for controlling the first control means so that the first control means go from an inactive state to an active state when the detection means detect an amplitude of expansion of the dilation member the less dilated and that the control means detect that the expansion amplitude of the dilated expansion member has exceeded a predefined threshold.

Apparatus according to claim 2 wherein the first control means changes from an active state to an inactive state when the detecting means detects a dilation amplitude of the least dilated dilation member and the control means detects that the amplitude of expansion of the least dilated dilation member has passed below a predefined threshold.

Device according to any one of the preceding claims wherein the means for detecting the amplitude of expansion of the least dilated expansion member comprise a rigid frame (7) configured to cooperate with the first control means and fixed rigidly to one of the ends of the first dilation member (2) and the second dilation member (3) so that the frame (7) has only one degree of freedom relative to the first and second expansion members (2). -3).

Device according to any one of the preceding claims, comprising second control means connected to the means for detecting an expansion amplitude differential between the first expansion member (2) and the second expansion member (3) and configured to transition from an idle state to an active state when the detecting means detects a nonzero expansion amplitude differential.

Device according to the preceding claim wherein the second control means are configured to operate at least one rotational movement along an axis of rotation (18) to the member to move which are integral with the first expansion member (2) and the second dilation member (3).

Apparatus according to any one of the preceding claims wherein the first expansion member (2) and the second dilation member (3) are configured to expand in a longitudinal direction so as to generate a translational movement.

Device according to the preceding claim comprising means for transforming a translation movement of the first expansion member (2) and / or the second expansion member (3) into a rotational movement along an axis of rotation (18) when the means for detecting an expansion amplitude differential between the first dilation member (2) and the second dilation member (3) detect a non-zero expansion amplitude differential.

Device according to the preceding claim in combination with claim 6 wherein the second control means comprise a coupling member configured to associate with the first rotational movement a second rotational movement according to the first rotational movement along an axis of rotation (18). .

Device according to the preceding claim wherein the first rotational movement and the second rotational movement are substantially perpendicular axes.

1 1. Device according to any one of claims 7 to 10 comprising means for amplifying the displacement in translation of the first dilation member (2) and the second expansion member (3).

Device according to any one of the preceding claims, comprising at least one screen (10) arranged to separate the first dilation member (2) from the second expansion member (3) and to project a shadow depending on the displacement of the sun on one of the two organs dilation (2-3) and / or function of the position of the two expansion members (2-3).

Device according to any one of the preceding claims, in which the second control means are intended for monitoring the movement of the sun in azimuth and / or in elevation.

A light ray reflection system comprising a tracking device (1) according to claims 1 to 13 and a plurality of articulated movable blades (22) configured to cooperate and be controlled by the device (1).

15. solar collector panel system comprising a tracking device (1) according to any one of claims 1 to 13 and at least one solar collector means configured to cooperate and be controlled by the device (1).