RU238711U1 - Elastic support of the front leaf spring suspension of the car - Google Patents

Abstract

This utility model pertains to transport engineering, specifically to upgrading the dependent front suspension of a Gazelle Business vehicle with leaf springs. The technical result achieved by this utility model is to reduce the level of shock loads and vibrations transmitted from the road to the vehicle body, thereby improving the vehicle's ride quality when loaded. The claimed technical result is achieved in that an elastic support is additionally introduced into the front leaf spring suspension of the vehicle, comprising a coil spring, lower and upper supports, wherein the coil spring is located coaxially with the standard compression buffer between the lower support and the upper support, the lower support is made in the form of a support cup connected to a support plate with mounting holes, and is secured to the leaf spring by a bolted connection by means of at least one pressure plate placed under the spring pack and tightened with studs and nuts, and the upper support is made in the form of a spacer installed between the base of the compression buffer and the frame shelf.

Description

The utility model relates to the field of transport engineering, in particular to the modernization of the dependent front suspension of the Gazelle Business type vehicle with leaf springs.

The basic front suspension of the Gazelle Business vehicle is known with a dependent front axle beam, using longitudinal leaf springs, telescopic hydraulic shock absorbers, and a rubber compression buffer. This suspension design is as follows: the front axle beam is rigidly connected to the springs by U-shaped clamps through the spring cover; the front end of each spring is secured to the front frame bracket, and the rear end is secured to the frame side member through a clevis (which compensates for changes in spring length during suspension travel). The spring is a small-leaf spring, consisting of two leaves pulled together by a clamp and a central bolt. The hinge joints of the springs and clevises, as well as the shock absorber mounts, are equipped with rubber-metal bushings for shock absorption. A rubber compression buffer is mounted above each spring on the frame, limiting the upward travel of the suspension. Two telescopic twin-tube shock absorbers are used as damping elements: their lower ends are attached to the bridge beam, and their upper ends are attached to brackets on the frame.

Thus, the basic front suspension of the Gazelle Business is a dependent leaf spring suspension with shock absorbers and travel limiters. The disadvantages of this design include insufficient damping of vertical and lateral body vibrations, both under load and unloaded, resulting in a reduced ride quality when driving over uneven surfaces. When loaded, the rigid leaf springs provide inadequate damping of small bumps, and the compression buffers, with frequent contact, transmit shocks to the frame. Prior art contains solutions aimed at improving suspension performance. For example, utility model RU 46716 U1 describes a front suspension with trailing arms and coil springs instead of leaf springs, which improves cornering rigidity and damping efficiency.

There are known solutions that install pneumatic spring elements (air springs) on the springs, which activate under load. However, such designs require connecting a pneumatic system, modifying the hydraulics, or electrical controls, which complicates the design.

Also known is patent US 11421748 B2, which discloses an additional coil spring support for installation on a vehicle's leaf spring to compensate for and improve the shock-absorbing capabilities of the existing suspension. However, this solution requires mounting the support cup directly on the spring without securing it to the frame or travel stop. Consequently, the spring does not operate coaxially with the standard compression damper, and the overall design requires complex coil fixation within a grooved cylindrical cup. Furthermore, the device is designed for universal installation and does not take into account the specific features of the Gazelle Business-type front suspension, specifically the presence of U-bolts and the limited mounting space between the spring and frame.

The technical result achieved by this utility model is to reduce the level of shock loads and vibrations transmitted from the road to the body, thereby improving the smoothness of the vehicle's ride when loaded. In other words, it improves the damping efficiency of vertical and lateral vibrations in a suspension with longitudinal springs, especially on small bumps and when the vehicle is loaded.

The claimed technical result is achieved in that an elastic support is additionally introduced into the front leaf spring suspension of the vehicle, comprising a coil spring, lower and upper supports, wherein the coil spring is located coaxially with the standard compression buffer between the lower support and the upper support, the lower support is made in the form of a support cup connected to a support plate with mounting holes, and is secured to the leaf spring by a bolted connection by means of at least one pressure plate placed under the spring pack and tightened with studs and nuts, and the upper support is made in the form of a spacer installed between the base of the compression buffer and the frame shelf.

The proposed utility model achieves the stated technical result by introducing an additional elastic element into the standard design. The front suspension of the aforementioned vehicle is improved by installing an additional elastic support in the form of a coil spring, positioned between the leaf spring and the compression damper. The lower end of the spring rests on the spring via a metal support cup, into which the spring is installed with a spacer pre-installed on the lower coil. This cup (lower support) is mounted on top of the leaf spring and secured with bolted connections using pressure plates under the spring pack. The upper end of the spring rests against an upper spacer installed between the base of the standard compression damper and the frame shelf. The spacer serves as a support surface for the upper coil of the spring and simultaneously serves as an intermediate element for reinstalling the damper. This upper spacer displaces the damper downward and forms a support plane for the upper coil of the spring. The suspension upgrade kit includes: a coil spring; a support cup with a damping spacer; a spacer for the compression buffer; and fasteners and clamping elements (bolts, nuts, plates) for installing the cup on the spring.

The length and stiffness of the additional spring are selected such that, when installed (assembled), it is pre-tensioned between the supports and functions as an additional elastic element, contributing to the suspension's operation under load. During the suspension's upward travel (compression), the spring is in elastic contact between the leaf spring and the frame and supports part of the load. Thus, under load, an additional elastic element, operating parallel to the leaf spring, contributes to the suspension's operation. All new components (the spring and its supports) are positioned coaxially with the standard compression damper and require no modifications to the basic suspension components (axle beam, U-bolts, shock absorbers, etc.), simplifying the upgrade.

The advantages of the proposed solution include improved ride comfort due to the suspension's increased damping ability and the ability of the spring to absorb road shock loads. The additional spring relieves the main leaf springs when driving over uneven surfaces, softening the suspension's operation. This reduces the frequency of the rigid compression damper's operation and dampens body vibrations more effectively. The original Gazelle Business suspension layout is preserved, complemented by the proposed utility model. This improves suspension performance without significantly complicating or increasing the weight of the design.

The proposed front suspension with an additional spring is industrially applicable: all its components can be manufactured using standard methods (for example, the spring can be cold-wound; the support parts can be made from rolled steel and then welded), and installation is possible using standard mounting points without welding or drilling. Thus, the combination of the stated features ensures a unified technical result – reduced shock loads and vibrations transmitted to the body, and, as a result, improved ride comfort under load.

Fig. 1 shows the elastic support of the front spring suspension of the vehicle.

The drawing shows a device installed between the leaf spring and the vehicle frame, which includes the following structural elements:

1 - a coil spring serving as an additional elastic element in the suspension;

2 - a support cup into which the lower part of the spring is inserted and which serves as a guide support;

3 - a support plate of the glass, connected to the support glass and having mounting holes;

4 - pressure plate placed under the leaf spring;

5 - compression stroke buffer;

6 - fastening studs with nuts, tightening the cup and the pressure plate;

7 - upper spacer.

The device is mounted on the front suspension in stages, using the standard vehicle mounting points and without the need to make changes to the basic suspension components (no welding or drilling):

1. Installing the lower spring support

An elastic spacer (not shown in Fig. 1) is placed on the lower coil of the additional coil spring (1). This spacer can be made, for example, of a polymer or composite material. This spacer is designed to dampen impact loads and prevent direct contact between the metal coil and the supporting surface. The lower end of the spring is inserted into the support cup (2), which is a cup-shaped guide element connected to the support plate (3), which is equipped with mounting holes.

The support is mounted on the leaf spring so that the studs (6), passing through the holes in the support plate (3), are positioned on either side of the spring pack. The studs are held together from below by a pressure plate (4), which is comprised of at least one metal component positioned beneath the spring. The pressure plate may be a single element matching the dimensions of the support plate (3), or it may be comprised of two separate sections mounted on opposite sides of the spring.

After all components are installed, the assembly is secured with nuts to the studs (6), ensuring a strong, tight connection without the need for drilling or welding. This solution preserves the integrity of the spring pack and ensures a secure attachment of the support to the suspension.

2. Installing the upper spacer (support) under the buffer

The stock compression damper (5), mounted on the lower flange of the frame side member, is first removed. An upper spacer (7) is installed between the damper base and the frame flange. This spacer increases the distance from the frame to the damper and simultaneously serves as a support surface for the upper coil of the spring (1). The spacer (7) can be made of an engineering polymer, elastomer, or metal, depending on stiffness and service life requirements. After installing the spacer, the damper (5) is returned to its original position and secured with the stock fasteners. This causes its working surface to shift downward relative to its original position, creating a fixed support upon which the spring subsequently rests.

3. Installing the spring on the car

Since the free length of the coil spring (1) exceeds the clearance between the spring and the upper spacer (7) installed under the compression buffer (5), the spring must be inserted into the assembly in a pre-compressed state or the clearance in the installation area must be temporarily increased. This can be accomplished in two ways.

First, the spring (1) is compressed outside the suspension using special clamping devices (e.g., turnbuckles or clamps). In the compressed state, the spring is carefully positioned between the support cup (2), secured to the spring, and the upper spacer (7), mounted on the frame. After the coils are aligned with the supporting surfaces, the clamps are gradually released, and the spring assumes its operating position under preload.

Secondly, the clearance can be temporarily increased by partially unloading the spring. To do this, disconnect the rear spring mount (e.g., the shackle bolt), causing the spring pack to drop downward under its own weight. This provides sufficient space for installing the pre-assembled module, which includes the support cup (2), spring (1), and upper spacer (7). After installation, the spring is returned to its operating position using a jack or other lifting device, allowing for controlled lifting of the spring until the mounting holes align. The shackle is then reinstalled and the fasteners tightened. This method may be preferable if specialized tools are not available, as it requires only standard equipment, such as a jack and mechanic's tools, and ensures secure installation of the spring without pre-compression.

After assembly, the additional spring is in constant elastic contact with the compression buffer at the top and the support cup at the bottom. The use of spacers prevents the spring from directly contacting the metal surfaces of the supports, preventing noise and dampening vibration. The design is such that when the vehicle is unloaded, the spring creates a negligible additional force and has virtually no effect on suspension rigidity. As the load increases (when the vehicle is loaded or when a wheel hits an obstacle), the spring comes into play, absorbing some of the vertical loads previously borne entirely by the spring alone. This reduces spring deflection, the frequency and amplitude of spring contact with the rigid buffer, reduces front end sag under load, and increases suspension energy capacity. Additional elastic elements (rubber spacers) in the unit provide vibration damping and eliminate shock loads and spring noise.

Claims (6)

1. An elastic support for a front leaf spring suspension of a vehicle, comprising a coil spring, a lower support and an upper support, characterized in that the coil spring is located coaxially with the standard compression buffer between the lower support and the upper support, the lower support is made in the form of a support cup connected to a support plate with mounting holes and secured to a leaf spring by a bolted connection by means of at least one pressure plate placed under the spring pack, the upper support is made in the form of a spacer installed between the base of the compression buffer and the frame shelf. 2. An elastic support for the front spring suspension of a vehicle according to paragraph 1, characterized in that the support cup has a cup-shaped form. 3. An elastic support for the front spring suspension of a vehicle according to paragraph 1, characterized in that the pressure plate is made in the form of a single element corresponding to the dimensions of the support plate. 4. An elastic support for the front spring suspension of a vehicle according to paragraph 1, characterized in that the pressure plate is made in the form of two separate plates. 5. An elastic support for the front leaf spring suspension of a vehicle according to any of paragraphs 1-4, characterized in that an elastic spacer is placed on the lower coil of the spring. 6. An elastic support for the front leaf spring suspension of a vehicle according to any of paragraphs 1-5, characterized in that the upper spacer is made of metal or elastomer.